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Investigation of the protective action of the E₂ prostaglandins on the gastric mucosa Bolton, John Philip 1977

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AN INVESTIGATION OF THE PROTECTIVE ACTION OF THE E  2  PROSTAGLANDINS  ON THE GASTRIC MUCOSA  BY JOHN PHILIP BOLTON B . C h i r . U n i v e r s i t y o f Cambridge M.A., M.B. U n i v e r s i t y o f Cambridge  1967 1968  A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENT OF THE DEGREE OF MASTER OF SCIENCE IN THE DEPARTMENT OF SURGERY a c c e p t t h i s t h e s i s as conforming t o the r e q u i r e d  The  University of B r i t i s h JUNE 1977  (c)  John P h i l i p  Bolton  Columbia  standard  In p r e s e n t i n g t h i s  thesis  in p a r t i a l  fulfilment of  the requirements f o r  an advanced degree at the U n i v e r s i t y of B r i t i s h Columbia, the L i b r a r y s h a l l I  f u r t h e r agree  make i t  freely available  that permission  for  I agree  that  reference and study.  f o r e x t e n s i v e copying o f  this  thesis  f o r s c h o l a r l y purposes may be granted by the Head of my Department or by h i s of  representatives.  this  thesis  It  is understood that copying or p u b l i c a t i o n  f o r f i n a n c i a l gain s h a l l  written permission.  Department o f  Surgery  The U n i v e r s i t y o f B r i t i s h 2075 W e s b r o o k P l a c e V a n c o u v e r , Canada V6T 1W5  Date  A  P  r i l  2  9 . 1977  Columbia  not be allowed without my  ABSTRACT  The p r o s t a g l a n d i n s  a r e found throughout the body and a r e t h e r e f o r e  thought t o have some p h y s i o l o g i c a l r o l e . prostaglandin  I t has been suggested t h a t  i s concerned w i t h the maintenance o f g a s t r i c mucosal  integrity.  In a p r e v i o u s  study o f the g a s t r i c e f f e c t s o f the E^ p r o s t a g l a n d i n s ,  n a t u r a l p r o s t a g l a n d i n E^ (PGE^) , 15-methyl p r o s t a g l a n d i n E^ (15M), and 16.16-dimethyl p r o s t a g l a n d i n E^ (16DM), i t was observed t h a t a l l t h r e e agents appeared t o i n c r e a s e mucus p r o d u c t i o n stimulate a non-acid of t h e  and t h a t 16DM appeared t o  s e c r e t i o n i n b a s a l Heidenhain pouches.  p r o s t a g l a n d i n s have been s t u d i e d i n d e t a i l .  These p r o p e r t i e s  (Experiments 1 and 2)  I t has p r e v i o u s l y been shown t h a t 15M can p r e v e n t  t h e damaging  e f f e c t o f a s p i r i n and indomethaciri on the g a s t r i c mucosal b a r r i e r . U s i n g a model i n which g a s t r i c mucosal b a r r i e r damage c o u l d be produced and  s u s t a i n e d , t h e a b i l i t y o f these  damage was s t u d i e d .  Experiment 1:  agents t o r e v e r s e e s t a b l i s h e d  (Experiment 3)  The e f f e c t o f t o p i c a l and i n t r a v e n o u s  E^ p r o s t a g l a n d i n s on  g a s t r i c mucus p r o d u c t i o n was s t u d i e d i n r a t s by measuring both t h e amount of mucus shed i n t o a s m a l l volume o f normal s a l i n e i n t h e c l o s e d stomach and  the amount o f mucus bound t o t h e mucosa, o v e r a t h r e e hour p e r i o d .  Mucus was measured i n d i r e c t l y by measuring the b i n d i n g o f A l c i a n B l u e . A l l p r o s t a g l a n d i n s caused a s i g n i f i c a n t i n c r e a s e i n the mucus found i n s o l u t i o n , but n o t i n t h a t bound t o t h e mucosa.  Experiment 2:  The e f f e c t o f t o p i c a l and i n t r a v e n o u s  t h r e e E^ p r o s t a g l a n d i n s perfused  canine  non-acid  solution.  on n o n - p a r i e t a l c e l l  Heidenhain pouches.  s e c r e t i o n was measured i n  The pouches were p e r f u s e d  The i n c r e a s e i n volume was measured u s i n g  g l y c o l as a volume marker and t h e HCO^ titration.  a d m i n i s t r a t i o n o f the  content  with a polyethylene  by t h e method o f back  16DM was found t o cause a s i g n i f i c a n t i n c r e a s e i n t h e volume,  and t h e f l u i d  secreted contained  Na , C l +  a c i d i t i s suggested t h a t t h i s r e p r e s e n t s  and HCO^ .  In t h e absence o f  s t i m u l a t i o n of n o n - p a r i e t a l  cells.  Experiment 3;  The r e v e r s a l o f a s p i r i n . induced  damage t o the g a s t r i c  mucosal b a r r i e r was demonstrated i n p e r f u s e d  canine  The  a s p i r i n t o produce g a s t r i c  pouches were p e r f u s e d  f o r two hours w i t h  Heidenhain pouches.  mucosal b a r r i e r damage, the a s p i r i n was then withdrawn and t h e pouch perfused  with a c i d alone.  prostaglandins  The e f f e c t s o f t o p i c a l and  and i n t r a v e n o u s  metiamide were t e s t e d d u r i n g t h i s  p e r i o d when e s t a b l i s h e d b a r r i e r damage e x i s t e d . reversed  intravenous  the damage, b u t t o p i c a l p r o s t a g l a n d i n s  latter  Intravenous P G E and i n t r a v e n o u s  2  and 15M  metiamide  did not. I t i s c o n c l u d e d t h a t t h e E^ p r o s t a g l a n d i n s on .the b a s a l g a s t r i c mucosa, c a u s i n g in non-parietal c e l l  secretion.  have a s e c r e t o r y  effect  an i n c r e a s e i n mucus p r o d u c t i o n and  This p r e v i o u s l y unrecognised s t i m u l a t i o n  of a c t i v e s e c r e t i o n has l e a d t o t h e m i s i n t e r p r e t a t i o n o f p e r m e a b i l i t y d a t a f o r 16DM.  These s e c r e t o r y e f f e c t s may have some p r o t e c t i v e a c t i o n .  Intravenous PGE^ and 15M can r e v e r s e damage i n t h e dog. for  e s t a b l i s h e d g a s t r i c mucosal b a r r i e r  T h i s i n d i c a t e s the p o s s i b i l i t y o f a therapeutic r o l e  these agents i n t h e management o f c o n d i t i o n s a s s o c i a t e d w i t h d i s r u p t i o n  of t h e g a s t r i c mucosal b a r r i e r .  iv  TABLE OF CONTENTS PAGE ABSTRACT LIST OF TABLES LIST OF FIGURES ACKNOWLEDGEMENTS  i i v ix x  INTRODUCTION  1  REVIEW OF THE LITERATURE The The  prostaglandins E^ p r o s t a g l a n d i n s  and the stomach and the g a s t r i c mucosal b a r r i e r  4 10  PURPOSE OF THE STUDY Mucus p r o d u c t i o n Non-parietal c e l l secretion E f f e c t o f the p r o s t a g l a n d i n s on e s t a b l i s h e d g a s t r i c mucosal b a r r i e r damage.  14 17 19  MUCUS PRODUCTION IN THE RAT (EXPERIMENT 1) M a t e r i a l and Methods Results NONPARIETAL CELL SECRETION IN THE DOG  22 30 (EXPERIMENT 2)  M a t e r i a l and Methods Results  36 42  EFFECT ON ESTABLISHED GASTRIC MUCOSAL BARRIER DAMAGE (EXPERIMENT 3) V a l i d a t i o n o f model M a t e r i a l and Methods Results  51 55 56  DISCUSSION  61  CONCLUSION  75  TABLES  76  XVII - XLV1  BIBLIOGRAPHY  105  APPENDIX A n t i s e c r e t o r y a c t i o n o f Metiamide E f f e c t o f d i l u t i o n o f A l c i a n Blue  114 116  LIST OF TABLES PAGE 1.  A l c i a n Blue b i n d i n g , volume s e c r e t i o n and  31  a c i d output w i t h t o p i c a l p r o s t a g l a n d i n s . 11.  A l c i a n Blue b i n d i n g , volume s e c r e t i o n and a c i d output w i t h i n t r a v e n o u s  111.  IV. V.  prostaglandins.  A l c i a n Blue b i n d i n g , volume s e c r e t i o n and a c i d output w i t h subcutaneous  34  histamine.  A l c i a n Blue b i n d i n g by r a t plasma. Volume and b i c a r b o n a t e  32  35  s e c r e t i o n from  Heidenhain  44  Heidenhain  45  pouches w i t h t o p i c a l p r o s t a g l a n d i n s . VI.  Volume and b i c a r b o n a t e  s e c r e t i o n from  pouches w i t h i n t r a v e n o u s Vll.  prostaglandins.  Net i o n f l u x e s i n Heidenhain  pouches w i t h  46  topical prostaglandins. Vlll.  P e r m e a b i l i t y f a c t o r s i n Heidenhain  pouches w i t h  47  topical prostaglandins. IX.  Net i o n f l u x e s i n Heidenhain intravenous  X.  pouches w i t h  49  prostaglandins.  P e r m e a b i l i t y f a c t o r s i n Heidenhain  pouches w i t h  50  intravenous.prostaglandins. XI.  Net i o n f l u x and p e r m e a b i l i t y f a c t o r s d u r i n g and f o l l o w i n g t o p i c a l a p p l i c a t i o n o f 20 mM  Xll.  Xlll.  aspirin.  Comparison o f n e t i o n f l u x and p e r m e a b i l i t y f a c t o r s in  a l l groups d u r i n g exposure t o 20 mM  54  57  aspirin.  Treatment o f e s t a b l i s h e d g a s t r i c mucosal b a r r i e r damage w i t h t o p i c a l p r o s t a g l a n d i n s .  58  VI  PAGE XIV.  Treatment o f e s t a b l i s h e d g a s t r i c mucosal  60  b a r r i e r damage w i t h i n t r a v e n o u s p r o s t a g l a n d i n s . XV.  Net i o n f l u x i n Heidenhain pouches w i t h  topical  68  16.16-dimethyl p r o s t a g l a n d i n E ( From the work o f P.E. XVI.  O'Brien and D.C.  Comparison o f the volume o f f l u i d produced  Carter ) by  72  acid  76  the Heidenhain pouches i n each group. XVll.  A l c i a n Blue b i n d i n g , volume s e c r e t i o n and output w i t h t o p i c a l p r o s t a g l a n d i n s .  XV111.  A l c i a n Blue b i n d i n g , volume s e c r e t i o n and output w i t h t o p i c a l  XlX.  XXI.  77  acid  78  acid  79  acid  80  16DM.  A l c i a n Blue b i n d i n g , volume s e c r e t i o n and output w i t h t o p i c a l  acid  15M.  A l c i a n B l u e b i n d i n g , volume s e c r e t i o n and output w i t h t o p i c a l  XX.  Controls.  PGE^.  A l c i a n Blue b i n d i n g , volume s e c r e t i o n and  output w i t h i n t r a v e n o u s p r o s t a g l a n d i n s . C o n t r o l s . XXll.  A l c i a n Blue b i n d i n g , volume s e c r e t i o n and output w i t h i n t r a v e n o u s  XX111.  XXIV.  81  acid  82  acid  83  15M.  A l c i a n B l u e b i n d i n g , volume s e c r e t i o n and output w i t h i n t r a v e n o u s  acid  16DM.  A l c i a n Blue b i n d i n g , volume s e c r e t i o n and output w i t h i n t r a v e n o u s PGE^.  XXV.  A l c i a n Blue b i n d i n g , volume s e c r e t i o n  and  a c i d output w i t h subcutaneous h i s t a m i n e . Controls.  84  V l l  PAGE XXVI.  XXVll.  A l c i a n Blue b i n d i n g , volume s e c r e t i o n and a c i d output  w i t h subcutaneous  Bicarbonate  s e c r e t i o n from H e i d e n h a i n  pouches t o p i c a l XXVlll.  86  prostaglandins.  Volume o f s e c r e t i o n from Heidenhain pouches t o p i c a l  XXIX.  histamine.  87  prostaglandins.  Net i o n f l u x and p e r m e a b i l i t y f a c t o r s . Experiments w i t h t o p i c a l  88  prostaglandins.  Controls. XXX.  Net i o n f l u x and p e r m e a b i l i t y f a c t o r s . Topical  XXXI.  89  15M.  Net i o n f l u x and p e r m e a b i l i t y f a c t o r s .  90  T o p i c a l 16DM., XXXll.  Net i o n f l u x and p e r m e a b i l i t y f a c t o r s .  91  T o p i c a l PGE 2  XXXlll.  Bicarbonate pouches.  XXXIV.  92  Intravenous p r o s t a g l a n d i n s .  Volume o f s e c r e t i o n from Heidenhain pouches.  XXXV.  s e c r e t i o n from Heidenhain  93  Intravenous p r o s t a g l a n d i n s .  Net i o n f l u x and p e r m e a b i l i t y f a c t o r s . Experiments w i t h  intravenous  94  prostaglandins.  Controls. XXXVI.  Net i o n f l u x and p e r m e a b i l i t y f a c t o r s . Intravenous  XXXVll.  15M.  Net i o n f l u x and p e r m e a b i l i t y f a c t o r s . Intravenous  95  16DM.  96  V J  PAGE XXXVlll.  Net i o n f l u x and p e r m e a b i l i t y f a c t o r s .  97  Intravenous PGE^. XXXlX.  Net i o n f l u x , p e r m e a b i l i t y f a c t o r s and  98  volumes s e c r e t e d i n Damage and Recovery Periods. XL.  Controls.  Net i o n f l u x , p e r m e a b i l i t y f a c t o r s and  99  volumes s e c r e t e d i n Damage and Recovery Periods. XLl.  A s p i r i n Damage.  Net i o n f l u x , p e r m e a b i l i t y f a c t o r s and  100  volumes s e c r e t e d i n Damage and Recovery Periods. XLll.  T o p i c a l PGE^.  Net i o n f l u x , p e r m e a b i l i t y f a c t o r s and  101  volumes s e c r e t e d i n Damage and Recovery Periods. XLlll.  T o p i c a l 15M.  Net i o n f l u x , p e r m e a b i l i t y f a c t o r s and  102  volumes s e c r e t e d i n Damage and Recovery Periods. XLlV.  Intravenous PGE . 2  Net i o n f l u x , p e r m e a b i l i t y f a c t o r s and  103  volumes s e c r e t e d i n Damage and Recovery Periods. XLV.  Intravenous 15M.  Net i o n f l u x , p e r m e a b i l i t y f a c t o r s and  104  volumes s e c r e t e d i n Damage and Recovery Periods. XLVl.  Intravenous Metiamide.  E f f e c t o f D i l u t i o n on A l c i a n Blue B i n d i n g .  117  I L  LIST OF FIGURES  The  r e l a t i o n s h i p o f PGE^  t o other pharmacologically  a c t i v e substances d e r i v e d from the same s o u r c e . The  s t r u c t u r e o f P r o s t a g l a n d i n E^, 15-methyl  p r o s t a g l a n d i n E^ and 16.16-dimethyl p r o s t a g l a n d i n V Standard curve f o r a l c i a n Blue Measurement o f f r e e mucus. Standard c u r v e f o r A l c i a n B l u e Measurement o f bound mucus. P e r f u s i o n system used i n the canine Heidenhain pouches. Standard curve f o r p o l y e t h y l e n e g l y c o l . The e x p e r i m e n t a l model used t o t e s t the  effect  of v a r i o u s drugs on e s t a b l i s h e d g a s t r i c mucosal b a r r i e r damage. The e f f e c t o f i n t r a v e n o u s metiamide on h i s t a m i n e stimulated acid  output.  X  ACKNOWLEDGEMENT  I wish t o thank my s u p e r v i s o r Dr. M.M. Cohen f o r h i s i n v a l u a b l e a d v i c e and guidance  d u r i n g the p e r i o d of t h i s  study.  E x p e r t t e c h n i c a l h e l p has been g i v e n by Mr. D. Palmer and Mr. N. A l l a d i n a and by Mrs.  C. Chan.  The work would n o t have been p o s s i b l e w i t h o u t  t h e i r help.  I wish t o thank t h e s t a f f members o f the Animal L a b o r a t o r y o f the Depart ment o f Surgery  f o r t h e i r h e l p and c o o p e r a t i o n .  I am i n d e b t e d t o Ms. G. Henderson f o r h e r o u t s t a n d i n g s e c r e t a r i a l h e l p and t o Mr. Frank Goudron and h i s s t a f f f o r t h e i r h e l p w i t h the o v e r a l l of t h i s  thesis.  production  1  INTRODUCTION  In 1933  Goldblatt"'" d i s c o v e r e d  an a c i d i c l i p i d s o l u b l e , smooth muscle  s t i m u l a t i n g compound i n seminal f l u i d . a prostaglandin  and  T h i s was  the  y e t i t went l a r g e l y u n n o t i c e d .  of i n a c t i v i t y i n the study o f t h i s compound due a b l e methods f o r a c c u r a t e a c t i v e components. d a t e s back t o the form  2  and  The  current high  prostaglandins  l e v e l o f i n t e r e s t i n the  4  and  the  c i r c u l a r muscle i n the  3  l a c k of  suit  prostaglandins  In the p a s t seventeen y e a r s  been done on these substances and  much  information  t h e i r pharmacological e f f e c t s .  are w i d e l y d i s t r i b u t e d i n the t i s s u e s o f the body  are known t o have a v a r i e t y of a c t i o n s .  of the u t e r u s  mainly t o the  a period  q u a n t i t a t i v e measurement of i t s  t h e i r chemical s t r u c t u r e s e l u c i d a t e d .  i s available regarding  and  There f o l l o w e d  1960's when these compounds were i s o l a t e d i n c r y s t a l l i n e  a v a s t amount o f work has  The  q u a l i t a t i v e and  f i r s t d e s c r i p t i o n of  Major e f f e c t s i n c l u d e  l o n g i t u d i n a l muscle o f the gut, gut  5  and  vasodilatation,  7  the  5  contraction  the i n h i b i t i o n  of  i n h i b i t i o n of g a s t r i c  8 acid secretion  and  the  a c c u m u l a t i o n of l a r g e volumes of f l u i d  i n the  small  . 9 intestine. led  T h e i r wide d i s t r i b u t i o n and  the v a r i e t y of t h e i r e f f e c t s has  t o the assumption t h a t they have a p h y s i o l o g i c a l r o l e .  such a r o l e e x i s t s , has  not y e t been determined and  t h a t the p r o s t a g l a n d i n s  may  be  simply  such as the endoperoxides or one donic  metabolites  step on  there  of o t h e r  This r o l e , i f i s now  evidence  a c t i v e agents  a m e t a b o l i c pathway from a r a c h i  a c i d t o p r o s t a c y c l i n , a h i g h l y p o t e n t agent r e c e n t l y i s o l a t e d from  vascular  t i s s u e . ^ (Figure 1)  or t h e i r a c t i v e p r e c u r s o r s take p l a c e  as r e q u i r e d , but  There i s no e v i d e n c e t h a t the  prostaglandins  are s t o r e d i n the t i s s u e s , b i o s y n t h e s i s the s t i m u l u s  f o r t h i s i s unknown.  The  seems t o agents  PROSTAGLANDIN SYNTHESIS  ARACHIDONIC ACID  CYCLIC ENDOPEROXIDES*  PGX:  THROMBOXANES *  PROSTACYCLIN* >  PGE_* PGF. * 2a  * Pharmacologically  FIGURE 1:  A c t i v e Substances  I l l u s t r a t e s the r e l a t i o n s h i p o f p r o s t a g l a n d i n E 2 t o a r a c h i d o n i c a c i d and o t h e r m e t a b o l i c a l l y r e l a t e d a c t i v e agents.  are thought t o be produced a t t h e s i t e o f t h e i r a c t i o n and they a r e known t o have an extremely s h o r t h a l f l i f e . the p r o s t a g l a n d i n s  I t i s p o s s i b l e t h a t the r e a s o n why  have been t h e agents most i n v e s t i g a t e d i s t h a t they a r e  more s t a b l e t h a n t h e i r a c t i v e p r e c u s o r s and have t h e r e f o r e been measured, i d e n t i f i e d and s y n t h e s i z e d  and have become w i d e l y a v a i l a b l e f o r l a b o r a t o r y  experimentation.  Although t h e debate r e g a r d i n g prostaglandins  t h e i r p h y s i o l o g i c a l a c t i o n continues the  have been shown t o have many p h a r m a c o l o g i c a l a c t i o n s and  they a r e c u r r e n t l y i n use o r under i n v e s t i g a t i o n as t h e r a p e u t i c  agents i n  a number o f f i e l d s .  Prostaglandin termination  i s used f o r the i n d u c t i o n o f labour"*"^ and f o r t h e  o f pregnanacy i n the f i r s t and second t r i m e s t e r .  11 12 '  I t also  i s used t o m a i n t a i n a p a t e n t ductus a r t e r i o s u s i n neonates w i t h major congenital cardiac abnormalities  who r e q u i r e the maintenance o f a l e f t t o  13 r i g h t shunt.  i t s value  C o n t r o l l e d c l i n i c a l t r i a l s a r e c u r r e n t l y underway t o study 14  i n erosive g a s t r i t i s  and t h e v a l u e  o f i t s o r a l l y a c t i v e methyl  analogues i n t h e treatment o f p e p t i c u l c e r a t i o n . ^ ' ^  4  REVIEW OF THE  LITERATURE  The E^ P r o s t a g l a n d i n s  and t h e Stomach  P r o s t a g l a n d i n - l i k e m a t e r i a l has been e x t r a c t e d from most p o r t i o n s o f 17 the g a s t r o i n t e s t i n a l t r a c t , of t h i s m a t e r i a l .  b u t t h e r e has been no formal c h a r a c t e r i z a t i o n  I t i s r e p o r t e d t h a t E and F p r o s t a g l a n d i n s  a r e t h e main  t y p e s o c c u r r i n g i n t h e gut and t h e m a t e r i a l e x t r a c t e d from the mucosa and 18 submucosa o f t h e stomach i s almost c e r t a i n l y PGE^. PGE^-like  The p r e s e n c e o f a  m a t e r i a l i n t h e g a s t r i c mucosa has s t i m u l a t e d  considerable  i n t e r e s t i n t h e e f f e c t o f t h i s n a t u r a l l y o c c u r r i n g p r o s t a g l a n d i n on g a s t r i c function. 2 ip o t e n t i n h i b i t o r o f g a s t r i c a c i d s e c r e t i o n when given 8 19 20 intravenously ' b u t i s almost i n a c t i v e when g i v e n o r a l l y . Analogues P G E  s  a  have been p r e p a r e d i n an attempt t o overcome t h i s disadvantage and a t t h e present  time two such analogues have been w i d e l y  i n v e s t i g a t e d , 15M and 16DM.  The d i f f e r e n c e s between these two analogues and the p a r e n t  compound a r e  i l l u s t r a t e d i n F i g u r e 2.  The term "the E^ p o s t a g l a n d i n s "  i s used t o i n c l u d e n a t u r a l PGE^ and  i t s two methyl analogues and as t h e e x p e r i m e n t a l  work i n t h i s t h e s i s i s  concerned w i t h c e r t a i n a c t i o n s o f these agents on t h e g a s t r i c mucosa c u r r e n t knowledge o f t h e i r g a s t r i c e f f e c t s i s reviewed.  The E^ p r o s t a g l a n d i n s  have two i m p o r t a n t a c t i o n s i n t h e stomach:  1.  I n h i b i t i o n of g a s t r i c a c i d secretion.  2.  P r o t e c t i o n o f t h e mucosa.  FIGURE 2:  I l l u s t r a t e s the s i m i l a r i t y i n s t r u c t u r e o f p r o s t a g l a n d i n E 2 and i t s methyl analogues 15-methyl p r o s t a g l a n d i n E 2 and 16.16dimethyl prostaglandin E 2  Inhibition of Gastric Acid  The  Secretion  accumulated evidence f o r i n h i b i t i o n o f a c i d s e c r e t i o n by  PGE^<and t h e c l o s e l y r e l a t e d PGE^ i s v e r y e x t e n s i v e  and i n c l u d e s  experiments i n man and a v a r i e t y o f animals under b a s a l and s t i m u l a t e d conditions.  As PGE^ was d i s c o v e r e d b e f o r e  PGE  2  i t has been more  e x t e n s i v e l y s t u d i e d , b u t no i m p o r t a n t d i f f e r e n c e s i n t h e i n h i b i t o r y a c t i o n s o f t h e two compounds have been found.  Animal  Studies  When g i v e n p a r e n t e r a l l y PGE^ can i n h i b i t g a s t r i c a c i d s e c r e t i o n i n dogs s t i m u l a t e d by a v a r i e t y o f agents i n c l u d i n g , pentagastrin,  histamine,  f o o d , 2-deoxy-D-glucose, r e s e r p i n e and c a r b a c h o l .  P a r e n t r a l PGE^ can i n h i b i t h i s t a m i n e  stimulated  secretion.  s e c r e t i o n i n r a t s can a l s o be i n h i b i t e d by p a r e n t e r a l g i v e n o r a l l y i n h i g h doses  (0.05-5 mg) i n an i s o s m o t i c  22  21  Basal  22 ~PGE^.  When  buffer  (Na^HPO^, pH 7.4) PGE^ can i n h i b i t g a s t r i c a c i d s e c r e t i o n o f p y l o r u s 22 ligated rats,  b u t i t i s i n e f f e c t i v e by t h i s route i n dogs.  In c o n t r a s t 15M and 16DM can i n h i b i t g a s t r i c a c i d s e c r e t i o n when g i v e n o r a l l y as w e l l as p a r e n t e r a l l y t o dogs and have a s i m i l a r 22 23 effect i n rats. potent  '  These agents have been found t o be much more  than t h e p a r e n t  longer duration.  The  E  compound and t o e x e r t a c t i v i t y f o r a much D  ^  Q  (dose i n h i b i t i n g a c i d output by 50%)  in  dogs f o r PGE^, 15M and 16DM a r e 10, 0.3 and 0.1 ug/Kg r e s p e c t i v e l y 22 with a s i n g l e intravenous i n j e c t i o n . O r a l 16DM i s 2.8 times as p o t e n t as 15M.  7  There i s e v i d e n c e t o suggest t h a t t h e mode o f a c t i o n o f t h e methyl analogues i s d i f f e r e n t when t h e d i f f e r e n t r o u t e s are used.  of administration  When a p p l i e d t o p i c a l l y t o t h e mucosa these agents appear  t o e x e r t a l o c a l a n t i s e c r e t o r y e f f e c t r a t h e r than a systemic secondary t o a b s o r p t i o n .  effect  Experiments on dogs w i t h two Heidenhain  pouches demonstrated t h a t l o c a l i n s t i l l a t i o n o f 16DM t o one pouch produced t o t a l i n h i b i t i o n o f s t i m u l a t e d a c i d s e c r e t i o n b u t was w i t h o u t e f f e c t i n the other.  A t h i g h e r doses a l e s s p o t e n t  c o u l d be demonstrated on t h e second pouch.  systemic  The systemic  effect  a c t i o n was 24  l e s s potent  and o f s h o r t e r d u r a t i o n than t h e l o c a l a c t i o n .  Human S t u d i e s Intravenous PGE^ w i l l i n h i b i t b a s a l  25  and p e n t a g a s t r i n  stimulated  19  20 a c i d s e c r e t i o n but o r a l administration i s without e f f e c t . the o t h e r hand g i v e n o r a l l y t o h e a l t h y  subjects i n h i b i t e d  s t i m u l a t e d a c i d o u t p u t f o r s e v e r a l hours, t h e ED  administered  and both analogues were p a r t i c u l a r l y  i n i n h i b i t i n g food induced  volunteers  approximately  16DM was a n t i s e c r e t o r y i n h e a l t h y v o l u n t e e r s when  both o r a l l y and i n t r a v e n o u s l y potent  pentagastrin  50  , 2 0 1 pg/Kg.  being  15M on  g a s t r i c s e c r e t i o n both i n h e a l t h y 27 and duodenal u l c e r p a t i e n t s .  8  P r o t e c t i o n o f the Mucosa  The  e v i d e n c e f o r t h i s a c t i o n comes under two headings:  A.  P r o t e c t i o n r e s u l t i n g from i n h i b i t i o n o f a c i d (antiulcer  B.  A.  secretion  effect).  P r o t e c t i o n independent o f a c i d s e c r e t o r y  P r o t e c t i o n R e s u l t i n g From I n h i b i t i o n o f A c i d  As t h e E^ p r o s t a g l a n d i n s  inhibition.  Secretion  have been demonstrated t o have  powerful a n t i s e c r e t o r y properties p o s s i b l e use f o r the p r e v e n t i o n  i n t e r e s t has a r i s e n i n t h e i r  and cure o f g a s t r o d u o d e n a l  ulcers.  PGE^ o r i t s methyl analogues g i v e n  e i t h e r subcutaneously o r  o r a l l y t o r a t s have been shown t o i n h i b i t g a s t r i c u l c e r s produced i n a v a r i e t y o f ways i n c l u d i n g :  ligation.  22  a)  Shay u l c e r s produced by p y l o r u s  b)  S t e r o i d induced u l c e r s .  c)  U l c e r s produced by o r a l and i n t r a p e r i t o n e a l  22  administration 28  of n o n s t e r o i d a l and  a n t i - i n f l a m m a t o r y agents, such as a s p i r i n  indomethacin.  2 9  9 PGE  2  o r 16DM  g i v e n e i t h e r o r a l l y o r subcutaneously i n h i b i t e d  i n a dose dependent manner the development o f duodenal u l c e r s produced i n r a t s by:  a)  A s i n g l e subcutaneous i n j e c t i o n of  b)  A constant carbachol  The  ,  histamine.^  subcutaneous i n f u s i o n o f h i s t a m i n e f o r 24  hours.  doses o f the p r o s t a g l a n d i n s  22  used i n these experiments were  i n the a c i d s e c r e t o r y i n h i b i t i n g range and e f f e c t s have been d e s c r i b e d  and  f o r other  i n h b i t o r s of acid secretion,  31 such as the H ^ - r e c e p t o r a n t a g o n i s t s ,  similar protective  32 '  used i n comparable  i n h i b i t o r y doses.  B.  P r o t e c t i o n Independent of A c i d S e c r e t o r y  Inhibition  Recent s t u d i e s suggest t h a t the p r o s t a g l a n d i n s have a p r o t e c t i v e a c t i o n u n r e l a t e d  to acid secretory  may  also  inhibition.  Robert has demonstrated t h a t a l c o h o l i n d u c e d e r o s i v e l e s i o n s o f the g l a n d u l a r p o r t i o n of the  f a s t e d r a t stomach can be  completely  p r e v e n t e d by the p r i o r a d m i n i s t r a t i o n o f 16.16-dimethyl PGA and  15-methyl PGF  acid secretion. 100  which are p r o s t a g l a n d i n s A l s o 16DM  administered  t h a t do not  2  inhibit  s u b c u t a n e o u s l y i n a dose  t i m e s l e s s t h a n the t h r e s h o l d dose i n h i b i t i n g a c i d s e c r e t i o n 33  i n the r a t w i l l a l s o p r e v e n t the development of these l e s i o n s . I t i s q u i t e c l e a r t h e r e f o r e t h a t the p r o s t a g l a n d i n s  can e x e r t  a  p r o t e c t i v e e f f e c t upon the g a s t r i c mucosa which i s independent o f acid secretory  inhibition.  10  A p o s s i b l e mechanism f o r t h i s p r o t e c t i v e of t h e g a s t r i c mucosal  The_l  Prostaglandins  0  effect i s tightening  barrier.  and the G a s t r i c  Mucosal  Barrier  In 1964 Davenport""** demonstrated t h a t t h e apparent i n h i b i t i o n o f a c i d secretion  caused by t h e t o p i c a l a p p l i c a t i o n  mucosa o f a H e i d e n h a i n pouch was  of eugenol t o the g a s t r i c  i n f a c t due t o back d i f f u s i o n o f hydrogen  i o n from the g a s t r i c lumen t o t h e i n t e r s t i t i a l  f l u i d o f the mucosa.  He  subsequently p o s t u l a t e d t h a t t h e e f f e c t o f b a r r i e r damaging a g e n t s , such as a s p i r i n , on the g a s t r i c mucosa was hydrogen i o n .  the r e s u l t o f the back d i f f u s i o n o f  The h i g h c o n c e n t r a t i o n o f hydrogen i o n i n t h e  interstitial  f l u i d damaged the mucosal c e l l s and the c a p i l l a r i e s and caused a r e l e a s e o f h i s t a m i n e which l e d t o v a s o d i l a t a t i o n ion.  and the s e c r e t i o n  o f more hydrogen  T h i s sequence o f e v e n t s l e d t o t h e shedding o f mucosal c e l l s ,  from t h e mucosal c a p i l l a r i e s and the t y p i c a l changes o f e r o s i v e  T h i s work l e d t o the r e v i v a l o f t h e concept o f the g a s t r i c  bleeding  gastritis.  35  mucosal  36 barrier.  Under normal c i r c u m s t a n c e s the c o n c e n t r a t i o n o f hydrogen i o n  and sodium i o n are unevenly d i s t r i b u t e d on e i t h e r mucosa.  s i d e o f the g a s t r i c  There i s a h i g h c o n c e n t r a t i o n o f hydrogen i o n i n the lumen and a  h i g h c o n c e n t r a t i o n o f sodium i n the i n t e r s t i t i a l  fluid.  Despite the  c o n c e n t r a t i o n g r a d i e n t s t h a t t h e r e f o r e e x i s t f o r these i o n s t h e r e i s l i t t l e movement o f hydrogen i o n o u t o f the lumen o r sodium i o n i n t o the The mucosa i s almost impermeable negative  concentration gradients.  mucosa i s r e f e r r e d  lumen.  t o the d i f f u s i o n o f t h e s e i o n s down t h e i r This r e l a t i v e impermeability  t o as the g a s t r i c mucosal b a r r i e r .  of the  The s m a l l movement  11  of  i o n s t h a t does o c c u r under normal c i r c u m s t a n c e s can be measured and  r e p r e s e n t s the b a s a l l e v e l o f t h e g a s t r i c mucosal p e r m e a b i l i t y .  Agents,  such as a s p i r i n , i n c r e a s e t h e p e r m e a b i l i t y o f the mucosa and t h e measured movement o f i o n s .  A s i g n i f i c a n t i n c r e a s e i n g a s t r i c mucosal p e r m e a b i l i t y  above the b a s a l l e v e l i n d i c a t e s  A variety  disruption  o f t h e g a s t r i c mucosal b a r r i e r .  o f agents a r e known t o break t h e g a s t r i c mucosal b a r r i e r ,  the  important ones b e i n g a s p i r i n ,  and  alcohol,  37 38 38 ' indomethacin, bile  salts  39  37 40 ' and a l l these agents cause e r o s i v e and hemorrhagic  of t h e g a s t r i c mucosa.  Hemorrhagic l e s i o n s  associated with stress  a l s o been shown t o be a s s o c i a t e d w i t h d i s r u p t i o n  lesion  have  o f t h e g a s t r i c mucosal  41 barrier.  D i s r u p t i o n o f t h e g a s t r i c mucosal b a r r i e r and t h e back d i f f u s i o n  o f hydrogen i o n a r e thought t o be major f a c t o r s acute hemorrhagic l e s i o n o f t h e g a s t r i c mucosa.  The  g a s t r i c mucosal b a r r i e r  i n the p a t h o g e n e s i s o f 42  i s a physiological  concept r a t h e r than a  t r u e a n a t o m i c a l e n t i t y , and i t i s n o t known how t h e v a r i o u s b a r r i e r b r e a k e r s produce t h e i r e f f e c t on t h e b a r r i e r .  I t has been suggested t h a t t h e  b a r r i e r i s formed by t h e t i g h t j u n c t i o n s t h a t  e x i s t between t h e l a t e r a l  b o r d e r s o f t h e mucosal c e l l s and t h a t b a r r i e r damage i s a s s o c i a t e d w i t h s e p a r a t i o n o f t h e t i g h t j u n c t i o n s which a l l o w s the passage o f i o n s between the  cells.  There i s e l e c t r o n  a b a r r i e r breaker that mucosa p r o t e i n  also  m i c r o s c o p i c e v i d e n c e t h a t when d i t h i o t h r e i t o l ,  causes plasma shedding, i s a p p l i e d  t o the  i s l o s t by p a s s i n g between a d j a c e n t mucosal c e l l s and t h e i r 43  disrupted tight junctions. the  same r o u t e .  I t i s probable that  i o n i c d i f f u s i o n o c c u r s by  12  The  possible r o l e of prostaglandins  b a r r i e r was r a i s e d anti-inflammatory  i n maintaining  the g a s t r i c mucosal  a f t e r Vane e t a l demonstrated t h a t c e r t a i n agents, i n p a r t i c u l a r a s p i r i n  could i n h i b i t the synthesis o f prostaglandins.  44  nonsteroidal  and indomethacin,  45  T h i s i n v i t r o e f f e c t has  46 s i n c e been demonstrated i n v i v o ,  and i t has been suggested t h a t these two  agents produce damage t o t h e g a s t r i c mucosal b a r r i e r by t h e i n h i b i t i o n o f endogenous p r o s t a g l a n d i n s y n t h e s i s , and t h e r e f o r e t h a t t h e p r o s t a g l a n d i n s are r e s p o n s i b l e f o r the maintenance o f g a s t r i c mucosal i n t e g r i t y . 47 Support f o r t h i s concept was p r o v i d e d by t h e experiments o f Cohen. s t u d i e d g a s t r i c mucosal p e r m e a b i l i t y i n canine  He  Heidenhain pouches and  demonstrated a h i g h l y s i g n i f i c a n t i n c r e a s e when a s p i r i n i n a c o n c e n t r a t i o n of 20 mM and indomethacin i n a c o n c e n t r a t i o n 2 mM were added t o t h e a c i d perfusate.  I n subsequent experiments he added 15M i n a dose o f 5 ug/Kg t o  the a c i d and a s p i r i n and a c i d and indomethacin p e r f u s a t e s and was able t o demonstrate t h a t i n t h e p r e s e n c e o f t h i s p r o s t a g l a n d i n a s p i r i n and indomethacin d i d n o t cause damage t o t h e g a s t r i c mucosal b a r r i e r .  The dose o f 15M was  the E D , _ Q f o r a c i d s e c r e t o r y i n h i b i t i o n , b u t t h i s same e f f e c t was w i t h a dose as low as 1.25 yg/Kg.  Cohen a l s o r e c o r d e d  achieved  i n t h i s experiment  t h a t when 15M was a p p l i e d t o t h e mucosa i n t h e absence o f t h e b a r r i e r breakers  i t decreased  suggesting  g a s t r i c mucosal p e r m e a b i l i t y below t h e c o n t r o l  t h a t exogenous p r o s t a g l a n d i n c o u l d n o t o n l y p r e v e n t  level,  damage t o  the g a s t r i c mucosal b a r r i e r b u t c o u l d a l s o t i g h t e n t h e g a s t r i c mucosal barrier.  F u r t h e r s t u d i e s o f t h e p e r m e a b i l i t y e f f e c t s o f the E ^ p r o s t a g l a n d i n s have been r e p o r t e d and have produced c o n f l i c t i n g d a t a .  O'Brien and C a r t e r  13  s t u d i e d t h e e f f e c t o f 16DM both t o p i c a l l y and i n t r a v e n o u s l y on t h e canine Heidenhain  pouch.  They found t h a t 16DM a p p l i e d t o p i c a l l y t o t h e mucosa i n  a c o n c e n t r a t i o n o f 15 ug/ml broke the g a s t r i c mucosal b a r r i e r , b u t d i d n o t 49 produce t h i s damaging e f f e c t when g i v e n s y s t e m i c a l l y . subsequently  B o l t o n and Cohen  studied the p e r m e a b i l i t y e f f e c t s o f a l l three  a d m i n i s t e r e d t o p i c a l l y and s y s t e m i c a l l y .  They were unable  prostaglandins t o confirm  Cohen's p r e v i o u s f i n d i n g t h a t 15M t i g h t e n e d t h e g a s t r i c mucosal b a r r i e r when a p p l i e d t o p i c a l l y .  U s i n g t h e same dose, and l a r g e r doses up t o t e n  times t h e o r i g i n a l dose, they found no s i g n i f i c a n t a l t e r a t i o n i n g a s t r i c mucosal p e r m e a b i l i t y .  However they d i d f i n d t h a t 15M t i g h t e n e d t h e  b a r r i e r when g i v e n i n t r a v e n o u s l y , an e f f e c t a l s o produced by i n t r a v e n o u s PGE . 2  They a l s o c o n f i r m e d  O'Brien  and C a r t e r ' s d a t a demonstrating d i s r u p t i o n  of t h e g a s t r i c mucosal b a r r i e r by t o p i c a l 16DM w i t h a c o n c e n t r a t i o n as low as 1 ug/ml and a l s o found  t h a t i t had t h e same e f f e c t s y s t e m i c a l l y i f g i v e n  by c o n s t a n t i n t r a v e n o u s i n f u s i o n as opposed t o t h e s i n g l e b o l u s used by O'Brien  The  injection  and C a r t e r .  apparent  d e t r i m e n t a l e f f e c t o f 16DM i s hard t o r e c o n c i l e w i t h t h e  f a c t t h a t i t i s a p o t e n t p r o t e c t o r o f t h e g a s t r i c mucosa.  14  PURPOSE OF THE  Evidence  STUDY '  has been p r e s e n t e d  t h a t the p r o s t a g l a n d i n s have a p r o t e c t i v e  a c t i o n on the g a s t r i c mucosa, an e f f e c t which i s u n r e l a t e d t o a c i d s e c r e t o r y i n h i b i t i o n and whose mechanism i s u n c e r t a i n .  As a r e s u l t o f p r e v i o u s o b s e r v a t i o n s c e r t a i n a s p e c t s o f t h e  gastric  e f f e c t s o f the E^ p r o s t a g l a n d i n s have been i n v e s t i g a t e d i n g r e a t e r depth.  1.  Mucus p r o d u c t i o n .  2.  Non-parietal c e l l secretion.  3.  The  e f f e c t o f E^ p r o s t a g l a n d i n s on e s t a b l i s h e d g a s t r i c mucosal  b a r r i e r damage.  1.  Mucus P r o d u c t i o n  When s t u d y i n g the p e r m e a b i l i t y e f f e c t s o f the  prostaglandins  49 i n c a n i n e Heidenhain  pouches  i t was  n o t i c e d t h a t i n the experiments  i n which p r o s t a g l a n d i n s were used the amount of s t r i n g y mucus i n the p e r f u s a t e was seemed p r o b a b l e  g r e a t e r than i n the c o n t r o l experiments.  mucus p r o d u c t i o n .  gastric  Robert e t a l ~ ^ when measuring the e f f e c t o f p r o s t a  g l a n d i n E^ on g a s t r i c s e c r e t i o n i n the r a t noted  The  There have been  p r e v i o u s r e f e r e n c e s t o the e f f e c t o f p r o s t a g l a n d i n s on  output  It  t h a t t h e p r o s t a g l a n d i n s were s t i m u l a t i n g mucus p r o d u c t i o n  and an attempt has been made t o q u a n t i f y t h i s e f f e c t . two  appearing  as measured by f u c o s e , hexosamine and  a r e d u c t i o n i n mucus  sialiac acid  dose a t which these o b s e r v a t i o n were made was  0.5  concentrations.  ug/Kg/minute.  15  At  l a r g e r doses the  marked i n h i b i t i o n or o v e r a l l g a s t r i c  produced volumes o f j u i c e too components o f mucus. that  These f i n d i n g s  15M  h i s t o l o g i c a l l y , but  o f mucus was  or g a s t r i t i s .  no  prostaglandin.  a l l the mucus i n the  T h i s was  to  Mucus i s found i n the  t o as  soluble  and  study stomach  have measured o n l y the  free  and  Most s t u d i e s of the  f r a c t i o n , and  and  o r f r e e mucus.  v a r i o u s s e c r e t o r y agents such as h i s t a m i n e , h i s t a l o g  Not  therefore action  and  because o f the  measurement have l a r g e l y i g n o r e d the  the  of  pentagastrin problems  barrier  A study o f mucus p r o d u c t i o n should i d e a l l y i n c l u d e  measurement o f b o t h  Because o f the  fractions.  problems o f r e c o v e r y o f b a r r i e r mucus any  c h r o n i c pouch p r e p a r a t i o n has of t h i s that the  a l s o been  assessed v i s u a l l y  gastric juice i s in solution,  term f r e e mucus i s more a c c u r a t e .  fraction.  masked  adherent t o the mucosa c a l l e d b a r r i e r mucus  gastric juice, referred  of r e c o v e r y and  was  I t has  component o f g a s t r i c s e c r e t i o n  problem of r e c o v e r y .  forms, t h a t  i n the  produced but  possibility  measurements were m a d e . ^  Mucus i s a d i f f i c u l t because o f the  no means exclude the  the  i n c r e a s e d g a s t r i c mucus f o r m a t i o n i n p a t i e n t s w i t h  either gastric ulcers  i n two  by  a c i d i n h i b i t o r y e f f e c t s o f the  reported that  that  s m a l l f o r b i o c h e m i c a l measurement o f  a t a h i g h e r dose s t i m u l a t i o n  by the  secretion  the  r a t was  severe l i m i t a t i o n s , and  i t was  chosen f o r t h i s study d e s p i t e the  form  because fact  that  i n i t i a l o b s e r v a t i o n s were made i n canine Heidenhain pouches.  Two  methods have been d e s c r i b e d f o r the  measurement of  of  barrier  16  mucus i n the r a t .  One  i n v o l v e s assessment by weight  and the  other  53 uses a t e c h n i q u e o f b i n d i n g t o a h i s t o l o g i c dye, l a t t e r method was measure the  A l c i a n Blue.  The  chosen because A l c i a n Blue can a l s o be used t o  f r e e f r a c t i o n o f mucus.  I t not o n l y b i n d s  the main c o n s t i t u e n t o f b a r r i e r mucus, but a l s o b i n d s 54 mucopolysaccharides,  to glycoprotein, to soluble  the main c o n s t i t u e n t o f the s o l u b l e f r a c t i o n ,  to  form i n s o l u b l e dye-mucus complexes. T h i s method a l l o w s prostaglandins  f o r the d e t e r m i n a t i o n  o f the e f f e c t o f  on both f r a c t i o n s o f mucus as w e l l as on the  amount o f mucus produced.  In o r d e r t o assess  s e c r e t o r y a c t i o n of the p r o s t a g l a n d i n s ,  total  the magnitude of  the  s t u d i e s were undertaken u s i n g  another agent known t o s t i m u l a t e mucus p r o d u c t i o n , Unfortunately  the  namely  histamine.  the o t h e r agents t h a t s t i m u l a t e mucus p r o d u c t i o n a l l  s t i m u l a t e g a s t r i c a c i d s e c r e t i o n and of experiments c o u l d not be s t i m u l a t i o n was  so the c o n d i t i o n s i n the two  identical.  sets  Mucus s e c r e t i o n d u r i n g a c i d  measured as a c o n v e n i e n t parameter f o r comparison.  17 2.  Non-Parietal C e l l Secretion  Topical and intravenous 16DM has been demonstrated to damage the gastric mucosal b a r r i e r i n perfused canine Heidenhain pouches, an action which would indicate a disruptive rather than a protective e f f e c t on the gastric mucosa as damage to the gastric mucosal b a r r i e r i s associated with damage to mucosal c e l l s and bleeding.  In d i r e c t  contrast to t h i s finding i t has been demonstrated that 16DM can protect the gastric mucosa from damage f i r s t l y by i t s antiulcer e f f e c t when used i n doses which i n h i b i t acid secretion and secondly by i t s protective e f f e c t i n doses 100 times less than the acid i n h i b i t o r y dose.  This discrepancy has been studied by re-examining the e f f e c t of 16DM i n the canine Heidenhain pouch.  49  In previous studies of gastric mucosal permeability,  which were  performed by perfusing a nonsecretory canine Heidenhain pouch with a solution containing H , N a , CI +  +  and PEG, the volume of any f l u i d  produced by the pouch could be assessed at the end of the three hour period of perfusion by subtracting the expected f i n a l volume ( i n i t i a l volume - sampling volume) from the measured f i n a l volume, calculated from the PEG concentration. The pouches produced some f l u i d even during the control perfusions, but i t was noted that i n the presence of 16DM the volume of f l u i d produced was greatly increased.  Similar increases were not observed  with the other two prostaglandins.  18  There a r e two p o s s i b l e e x p l a n a t i o n s production.  f o r the cause o f t h i s  fluid  Agents which damage t h e g a s t r i c mucosal b a r r i e r a l s o  cause a p r o d u c t i o n o f f l u i d by t h e pouch, so i t i s p o s s i b l e t h a t the increase i n f l u i d production  o c c u r r e d by t h e same mechanism o f an  i n c r e a s e i n g a s t r i c mucosal p e r m e a b i l i t y and t h e subsequent damaging e f f e c t o f t h e hydrogen i o n on t h e mucosa.  Doubt i s c a s t upon t h i s  e x p l a n a t i o n by t h e f a c t t h a t t h e degree o f damage produced by 16DM, assessed  by t h e i n c r e a s e i n g a s t r i c mucosal p e r m e a b i l i t y , was s m a l l  compared w i t h known b a r r i e r b r e a k e r s , was g r e a t e r .  y e t the volume o f f l u i d  produced  A second e x p l a n a t i o n i s t h a t 16DM s t i m u l a t e d a c t i v e  s e c r e t i o n by n o n p a r i e t a l c e l l s  i n the mucosa.  Such an e f f e c t c o u l d  account f o r the volume o f f l u i d produced, and a c t i v e s e c r e t i o n o f t h i s s o r t i n a system i n which c a l c u l a t i o n o f t h e p e r m e a b i l i t y f a c t o r i s based on t h e assumption t h a t t h e pouch i s e n t i r e l y n o n s e c r e t o r y lead t o d i s c r e p a n c i e s i n the p e r m e a b i l i t y  If the f i r s t  could  data.  explanation i s correct increased production of  f l u i d would o n l y o c c u r  i n t h e p r e s e n c e o f exogenous a c i d which c o u l d  d i f f u s e i n t o t h e mucosa as a r e s u l t o f the i n c r e a s e i n p e r m e a b i l i t y . In the absence o f a c i d t h e r e should be no i n c r e a s e d p r o d u c t i o n o f fluid.  On t h e o t h e r hand i f t h e f l u i d were due t o a c t i v e s e c r e t i o n  then i t would o c c u r  i n t h e p r e s e n c e o r absence o f a c i d .  Perfusion  experiments were t h e r e f o r e performed i n canine Heidenhain pouches i n which t h e e f f e c t o f t o p i c a l and i n t r a v e n o u s s t u d i e d when t h e p e r f u s a t e c o n t a i n e d i s o s m o t i c , and c o n t a i n e d  no a c i d .  L i , Na , C l +  +  E^ p r o s t a g l a n d i n s was The s o l u t i o n used was  and PEG.  L i t h i u m behaves i n  + 55 the same way as H i n r e s p e c t o f p e r m e a b i l i t y and can be used as an  19  indicator of permeability an a c c u r a t e  i n the absence o f H*".  i n d i c a t o r of permeability  Sodium would not  i f nonparietal c e l l secretion  were o c c u r r i n g as the s e c r e t e d f l u i d would c o n t a i n sodium i o n s . i s a volume marker, and of the p e r f u s a t e  The t o 16DM  The  the absence o f a c i d allowed  the HCO^  PEG  content  t o be measured.  production  o f f l u i d c o n t a i n i n g Na , +  CI  and  HCO^  i n response  i n the absence o f exogenous a c i d would i n d i c a t e d i r e c t  t i o n of nonparietal  3.  be  stimula  cells.  E f f e c t of the E^ P r o s t a g l a n d i n s  on E s t a b l i s h e d G a s t r i c Mucosal  B a r r i e r Damage  The and  i n h i b i t o r y e f f e c t o f the E ^ p r o s t a g l a n d i n s  the proven a n t i u l c e r e f f e c t i n e x p e r i m e n t a l  t h e i r study i n man PGE^ 15M  16DM,  are h i g h l y p o t e n t  16  and  the  s i z e o f the u l c e r  the two  methyl analogues,  w i l l reduce both the 15  i n p a t i e n t s with  agent i s not c u r r e n t l y i n g e n e r a l use,  and  severity of  on t o the  market w i l l g r e a t l y reduce i n t e r e s t i n the p r o s t a g l a n d i n s s e r i o u s s i d e e f f e c t o f the H ^ - r e c e p t o r a n t a g o n i s t s  the  However the  i t seems l i k e l y t h a t  r e c e n t i n t r o d u c t i o n o f the H ^ - r e c e p t o r a n t a g o n i s t s  may  Controlled  g a s t r i c and  duodenal u l c e r s , s i g n i f i c a n t l y b e t t e r then a p l a c e b o .  the p r o s t a g l a n d i n s  l e d to  i n h i b i t o r s by the o r a l r o u t e .  t r i a l s have demonstrated t h a t 15M pain  animals has  as t h e r a p e u t i c agents i n p e p t i c u c l e r a t i o n .  i s i n e f f e c t i v e when g i v e n o r a l l y , but and  on a c i d s e c r e t i o n  emerge.  the  European  unless However,  f i n d a r o l e i n the treatment o f acute g a s t r i c  mucosal l e s i o n s as t h e i r known g a s t r i c e f f e c t s are  particularly  20  appropriate t o t h i s condition.  The p a t h o g e n e s i s o f acute g a s t r i c mucosal  l e s i o n s i s complex b u t two f a c t o r s a r e o f p a r t i c u l a r importance, the 42  p r e s e n c e o f a c i d and d i s r u p t i o n  o f t h e g a s t r i c mucosal b a r r i e r .  The  m e d i c a l management o f b l e e d i n g from acute g a s t r i c mucosal  lesions  has  changed l i t t l e o v e r t h e p a s t 30 y e a r s and i s aimed p r i m a r i l y a t  r e d u c i n g t h e amount o f g a s t r i c a c i d p r e s e n t by n e u t r a l i z a t i o n and more recently the  by i n h i b i t i o n .  a b i l i t y to tighten  be o f g r e a t  An agent which combined a c i d i n h i b i t i o n w i t h  t h e g a s t r i c m u c o s a l . b a r r i e r would t h e o r e t i c a l l y  value.^  I t has p r e v i o u s l y  been demonstrated t h a t 15M can p r e v e n t damage  t o t h e g a s t r i c mucosal b a r r i e r by a s p i r i n and indomethacin, and t h i s could indicate a possible  prophylactic  role.  Before suggesting a  t h e r a p e u t i c r o l e i t would be n e c e s s a r y t o demonstrate t h a t t h e p r o s t a g l a n d i n s c o u l d a l s o r e v e r s e g a s t r i c mucosal b a r r i e r damage once i t was e s t a b l i s h e d .  An attempt has been made t o do t h i s u s i n g t h e  p e r f u s e d c a n i n e Heidenhain pouch.  Initially  i t was n e c e s s a r y t o d e s i g n a model i n which g a s t r i c  mucosal b a r r i e r damage c o u l d be produced and i n which t h e damage would p e r s i s t a f t e r w i t h d r a w a l o f t h e damaging agent, a s i t u a t i o n analagous to that for  encountered c l i n i c a l l y .  T h i s was done by p e r f u s i n g  two hours w i t h an a c i d and a s p i r i n s o l u t i o n and then  w i t h a c i d a l o n e f o r t h e t h i r d hour. the  t h e pouch  perfusing  The p e r s i s t e n c e o f damage d u r i n g  t h i r d hour would p r o v i d e t h e model on which t h e e f f e c t o f t h e  p r o s t a g l a n d i n s c o u l d be t e s t e d by a d d i n g them t o t h e p e r f u s a t e and g i v i n g them i n t r a v e n o u s l y d u r i n g the t h i r d hour.  As evidence has been  21  presented  t h a t the p r o t e c t i v e e f f e c t of the p r o s t a g l a n d i n s  r e l a t e d t o a c i d s e c r e t o r y i n h b i t i o n i t was simultaneously  decided  i s not  to investigate  the e f f e c t o f another type o f a n t i s e c r e t o r y agent,  H^-receptor antagonist, The  drug metiamide was  and  i s not  on e s t a b l i s h e d g a s t r i c mucosal b a r r i e r damage. used.  T h i s agent i n s o l u t i o n a c t s as a b u f f e r  suitable for addition to a c i d perfusates,  only i t s intravenous  an  e f f e c t s were s t u d i e d .  and  therefore  22  STUDY OF THE IN THE  EFFECTS OF THE  RAT  PROSTAGLANDINS ON  GASTRIC MUCUS PRODUCTION  (EXPERIMENT 1)  M a t e r i a l and Methods  (i)  P r e p a r a t i o n o f the A n i m a l s :  The  study was  W i s t a r r a t s weighing approximately laparotomy was ligated.  gm.  A f t e r an 18 hour f a s t a  performed under e t h e r a n a e s t h e s i a , and the esophagus  T h i s was  contents.  300  c a r r i e d out i n male  done t o p r e v e n t  Vagotomy was  esophageal l i g a t u r e .  s a l i v a contaminating  accomplished  A needle was  the  gastric  by i n c l u d i n g the v a g i i n the  passed from the duodenum through  the p y l o r u s , and 4 ml. o f the t e s t s o l u t i o n were i n j e c t e d i n t o stomach, the needle  withdrawn and the p y l o r u s l i g a t e d .  laparotomy, the r a t s were a l l o w e d three  After  t o r e c o v e r and then s a c r i f i c e d  at  hours.  Group I : The  the  The  e f f e c t of T o p i c a l A p p l i c a t i o n of the P r o s t a g l a n d i n s :  t e s t s o l u t i o n c o n s i s t e d o f 150 mM  c o n t r o l s and  150 mM  experimental  groups.  10 pg/ml and PGE^  sodium c h l o r i d e i n the  sodium c h l o r i d e p l u s the p r o s t a g l a n d i n i n the 15M  and 16DM  were added i n a c o n c e n t r a t i o n o f  i n a c o n c e n t r a t i o n of 100  ug/ml.  These c o n c e n t r a t i o n s  are s m a l l e r than the c o n c e n t r a t i o n s used i n experiments t o demonstrate the a n t i u l c e r p r o p e r t i e s of these agents and r e p r e s e n t doses of mg/Kg f o r 15M the  E D  gg  and  16DM  and  1.3  mg/Kg f o r P G E  2  which are l e s s  f o r i n h i b i t i o n of a c i d s e c r e t i o n i n p y l o r u s l i g a t e d  There were i n i t i a l l y 10 r a t s i n the c o n t r o l group and three experimental  groups, one  course o f the experiment.  r a t i n the PGE^  0.13  than rats.  i n each o f  the  group d i e d d u r i n g  the  23  Group I I ; The E f f e c t o f Intravenous The t e s t s o l u t i o n was 150 mM e x p e r i m e n t a l groups.  A d m i n i s t r a t i o n of P r o s t a g l a n d i n s :  sodium c h l o r i d e i n both c o n t r o l and  A f i n e p o l y e t h y l e n e cannula was p l a c e d c e p h a l a d  i n t h e i n f e r i o r vena cava and brought  t o the s u r f a c e through t h e  p o s t e r i o r abdominal w a l l f o r the r e p e a t e d a d m i n i s t r a t i o n o f the prostaglandins.  The p r o s t a g l a n d i n s were g i v e n by b o l u s  i n j e c t i o n through the c a n n u l a . f i r s t when the t e s t one  intravenous  Three i n j e c t i o n s were g i v e n :  the  s o l u t i o n was p l a c e d i n the stomach, and then a t  and two hours a f t e r w a r d s .  Each b o l u s dose o f 15M and 16DM  was 0.6 ug/Kg and each dose o f P G E  2  0.6 mg/Kg.  These doses a r e  below the ED^^ f o r i n h i b i t i o n o f a c i d s e c r e t i o n i n p y l o r u s l i g a t e d r a t s when these agents  are g i v e n subcutaneously.  There were  f i v e r a t s i n the c o n t r o l and each o f the t h r e e e x p e r i m e n t a l one  initially groups,  r a t i n the c o n t r o l group d i e d , and i n one r a t i n the 15M group  the cannula became d i s l o d g e d .  Group I I I :  The E f f e c t o f Subcutaneous A d m i n i s t r a t i o n o f Histamine  di-HCl:  The p r e p a r a t i o n o f the animals was the same as f o r the o t h e r groups.  The h i s t a m i n e was g i v e n by i n t e r m i t t e n t  i n j e c t i o n i n 1 ml o f normal s a l i n e . were g i v e n :  subcutaneous  Three subcutaneous i n j e c t i o n s  the f i r s t when t h e t e s t s o l u t i o n was p l a c e d i n the  stomach, and then a t one and two hours a f t e r w a r d s . was 6 mg/Kg.  Each b o l u s dose  The c o n t r o l animals r e c e i v e d normal s a l i n e .  were f i v e r a t s i n the c o n t r o l and e x p e r i m e n t a l  group.  There  24 (ii)  C o l l e c t i o n o f Samples: r a t s were s a c r i f i c e d .  A t t h e c o m p l e t i o n o f t h e experiment t h e The stomachs were removed, opened down t h e  l e s s e r c u r v a t u r e and t h e c o n t e n t s c o l l e c t e d .  The g a s t r i c  contents  were homogenised i n a Dounce homogeniser and t h e volume r e c o r d e d .  Analysis  1.  Hydrogen Ion:  The hydrogen i o n c o n c e n t r a t i o n was measured  by t i t r a t i o n a g a i n s t 0.1 N sodium h y d r o x i d e i n an automatic titrimeter  2.  Mucus:  (Radiometer  Copenhagen).  The mucus c o n t e n t was e s t i m a t e d by measuring t h e amount  of A l c i a n Blue bound t o t h e whole stomach and t o a sample o f the g a s t r i c c o n t e n t s .  The A l c i a n Blue used was A l c i a n  Blue  GX8.  A)  F r e e Mucus:  The dye b i n d i n g i n t h e g a s t r i c c o n t e n t s was 57  measured by t h e method o f P i p e r e t a l .  They s t u d i e d  a v a r i e t y o f c o n d i t i o n s which c o u l d i n f l u e n c e t h e A l c i a n Blue b i n d i n g p r o p e r t i e s o f g a s t r i c j u i c e mucoproteins  and  reached t h e f o l l o w i n g c o n c l u s i o n s : a)  Concentration of A l c i a n Blue: was  The c o n c e n t r a t i o n  v a r i e d between 2 and 100 mg/100 ml and maximum  p r e c i p i t a t i o n was o b t a i n e d a t 40 mg/100 ml. b)  pH o f t h e R e a c t i o n M i x t u r e :  Maximum p r e c i p i t a t i o n  of t h e dye was o b t a i n e d a t pH 6. c)  Temperature o f t h e R e a c t i o n M i x t u r e : was  No d i f f e r e n c e  found between b i n d i n g a t 20°C and 37° C.  25  d)  Time o f I n c u b a t i o n :  I t was found t h a t dye b i n d i n g  i n c r e a s e d w i t h time, t h e amount o f dye p r e c i p i t a t e d a t the end o f t h e 24 hours was almost double t h a t a t one hour e)  Ionic Strength of the Reaction Mixture:  Varying the  m o l a r i t y o f sodium c h l o r i d e was found t o have no e f f e c t on dye b i n d i n g . The o p t i m a l c o n d i t i o n s o u t l i n e d here were used i n these  experiments.  One m i l l i l i t r e o f t h e homogenised g a s t r i c c o n t e n t s was mixed w i t h 3.3 ml. o f M c l l v a i n e s c i t r a t e  phosphate  b u f f e r and 0.2 ml. o f A l c i a n Blue o f c o n c e n t r a t i o n 10 mg/ml and made t o 5 m l . w i t h d i s t i l l e d water.  The A l c i a n Blue  s o l u t i o n was f r e s h l y p r e p a r e d each day..  The c o n c e n t r a t i o n  of  A l c i a n Blue i n t h e r e a c t i o n mixture was 40 mg/100 ml and  the pH 5.8. for  The r e a c t i o n m i x t u r e was i n c u b a t e d a t 20°C  24 hours and then c e n t r i f u g e d a t 2500 r e v o l u t i o n s p e r  minute f o r 10 minutes.  The c o n c e n t r a t i o n o f A l c i a n Blue i n  the s u p e r n a t e n t f r a c t i o n was e s t i m a t e d s p e c t r o p h o t o m e t r i c a l l y at  615 nm and compared w i t h t h a t i n a tube c o n t a i n i n g t h e  i d e n t i c a l r e a g e n t s e x c e p t t h a t t h e g a s t r i c j u i c e was r e p l a c e d by b u f f e r .  Dye b i n d i n g was e x p r e s s e d as t h e amount o f  A l c i a n Blue i n m i l l i g r a m s p r e c i p i t a t e d from t h e r e a c t i o n mixture d u r i n g i n c u b a t i o n .  The  s t a n d a r d c u r v e f o r A l c i a n Blue i n t h i s  mixture i s shown i n F i g u r e 3.  reaction  The curve was c o n s t r u c t e d  SO  a> u c o  JO  o  JQ <  A l c i a n B l u e (mg/5 ml)  FIGURE 3:  The s t a n d a r d c u r v e f o r A l c i a n B l u e p r e p a r e d i n the r e a c t i o n m i x t u r e used f o r the measurement o f f r e e mucus.  27 from t r i p l i c a t e assays o f each c o n c e n t r a t i o n t e s t e d can be seen t o be b i p h a s i c . supernatant  One  o f each sample was  m i l l i l i t r e of of  d i l u t e d w i t h one  and  the  millilitre  o f b u f f e r p r i o r t o measuring the absorbance so t h a t a l l the absorbance r e a d i n g s  f e l l on the f i r s t p a r t of  the  curve.  An e r r o r c o u l d o c c u r plasma p r o t e i n s .  i f A l c i a n Blue bound t o  There i s always a s m a l l l e a k o f  plasma p r o t e i n s i n t o the g a s t r i c lumen and t h i s may i n c r e a s e d by an i n c r e a s e i n mucosal b l o o d  flow.  S t u d i e s were performed i n which plasma from a r a t used t o r e p l a c e d the g a s t r i c c o n t e n t s  be  was  i n the r e a c t i o n  mixture and the b i n d i n g measured.  B)  B a r r i e r Mucus;  T h i s was  estimated  by a m o d i f i c a t i o n  53 o f t h e method o f Corne e t a l . was  incubated  i n 25 ml.  The  everted  stomach  of M c l l v a i n e s c i t r a t e phosphate  b u f f e r c o n t a i n i n g A l c i a n Blue i n a c o n c e n t r a t i o n 40 mg/100 ml, removed and  f o r two  hours.  The  stomach was  of  then  the s o l u t i o n c e n t r i f u g e d a t 2500 r e v o l u t i o n s  p e r minute f o r 10 minutes and t h e c o n c e n t r a t i o n o f A l c i a n Blue e s t i m a t e d  spectrophotometrically.  b i n d i n g was  as the amount o f A l c i a n Blue  expressed  Dye  i n m i l l i g r a m s p r e c i p i t a t e d from the s o l u t i o n d u r i n g incubation.  28  The  s t a n d a r d curve f o r A l c i a n Blue i n M c l l v a i n e s  c i t r a t e phosphate b u f f e r i s shown i n F i g u r e 4. c o n s t r u c t e d i n the same way as the o t h e r curve and i s s i m i l a r l y b i p h a s i c .  The  I t was  standard  supernatant  samples were a l s o d i l u t e d w i t h b u f f e r t o b r i n g the absorbance r e a d i n g s i n t o the f i r s t p a r t o f the c u r v e .  Corne demonstrated by h i s t o l o g i c a l  examination  of the r a t stomach s t a i n e d f o r two hours w i t h  Alcian  Blue t h a t t h e r e was no p e n e t r a t i o n of the dye i n t o the mucosal t i s s u e .  (iv)  Statistical Analysis:  The r e s u l t s were a s s e s s e d u s i n g  t - t e s t f o r p a i r e d v a l u e s and a p p l y i n g the H o t e l l i n g  Student's  correction.  FIGURE 4:  The s t a n d a r d c u r v e f o r A l c i a n B l u e used i n the measurement o f bound mucus.  30  Results  The r e s u l t s o f the t o p i c a l a p p l i c a t i o n t a b u l a t e d i n Table  I and those  o f the p r o s t a g l a n d i n s a r e  f o r intravenous  administration are tabulated  i n Table I I .  P r o s t a g l a n d i n E^ had the same e f f e c t on mucus p r o d u c t i o n when g i v e n by either  route.  As can be seen from T a b l e  I and I I i t had no e f f e c t on b a r r i e r  mucus as measured by A l c i a n Blue bound t o the g a s t r i c mucosa b u t caused a h i g h l y s i g n i f i c a n t i n c r e a s e i n mucus i n the g a s t r i c the t o t a l amount o f mucus produced when a p p l i e d t o p i c a l l y  (p < 0.01).  (Table I ) , h a v i n g  Given i n t r a v e n o u s l y  (p < 0.01) and  16DM had a s i m i l a r  effect  no e f f e c t on b a r r i e r mucus b u t  causing a h i g h l y s i g n i f i c a n t increase i n free mucus.  contents  (p < 0.01) and t o t a l  (p < 0.01)  (Table I I ) t h e e f f e c t was l e s s marked.  There was  a s i g n i f i c a n t i n c r e a s e i n f r e e mucus (p < 0.05) b u t the o v e r a l l i n c r e a s e was not s i g n i f i c a n t .  15M g i v e n i n t r a v e n o u s l y caused the l a r g e s t  f r e e mucus (p < 0.01) and consequently but was w i t h o u t  i n f r e e mucus  i n the t o t a l mucus produced  e f f e c t on b a r r i e r mucus.  caused a r e d u c t i o n i n b a r r i e r mucus (p < 0.01) b u t without  increase i n  Given t o p i c a l l y  (p < 0.01)  (Table I)  (p < 0.01) and a c o r r e s p o n d i n g  i t increase  a s i g n i f i c a n t i n c r e a s e i n the t o t a l  amount.  The a l t e r a t i o n i n the volume and a c i d output produced by the t h r e e agents i s shown i n the T a b l e s . solution  instilled  Topical application  Four m i l l i l i t r e s was the volume o f t e s t  i n t o the stomach a t the onset o f the p r o s t a g l a n d i n s  o f the experiments.  caused an i n c r e a s e i n volume o f  between 1 and 3 ml., b e i n g g r e a t e s t w i t h PGE  0  and l e a s t w i t h  16DM.  ALCIAN BLUE BOUND ( i n mg.) EXPERIMENT CONTROL  NO.  VOLUME i n ml.  ACID OUTPUT yeq H /3 Hr  MUCOSA  CONTENTS  TOTAL  0.80 ±0.06  0.57 ±0.09  1.37 ±0.11  10  4.05 ±0.03  15M 10 yg/ml  10  5.45** ±0.27  23.1** ±5.9  0.45** ±0.08  1.44** ±0.19  1.89 ±0.25  16DM 10 yg/ml  10  5.07** ±0.08  20.4** ±3.2  0.67 ±0.13  1.66** ±0.30  2.33* ±0.35  6.82** ±0.41  12.7** ±5.82  0.71 ±0.19  2.16** ±0.505  2.88* ±0.55  PGE 100 yg/ml  70.4 ±10.2  ** = p < 0.01  TABLE I :  E f f e c t o f t o p i c a l E p r o s t a g l a n d i n s on A l c i a n B l u e b i n d i n g , volume s e c r e t e d and a c i d output i n the c l o s e d r a t stomach over 3 hours (Mean ± S.E.). 2  ALCIAN BLUE BOUND ( i n mg.) EXPERIMENT  NO.  CONTROL  4  15M 0.3 yg/Kg/Hr 16DM 0.3 yg/Kg/Hr PGE 0.3 mg/Kg/Hr  VOLUME i n ml.  ACID OUTPUT yeq H /3 Hr  MUCOSA  CONTENTS  TOTAL  3.88 ±0.12  40.75 ±7.78  0.71 ±0.04  1.60 ±0.18  2.31 ±0.22  4.33 ±0.02  82.4* ±13.2  0.98 ±0.03  4.72** ±0.11  5.82* ±0.04  4.04 ±0.02  45.1 ±7.7  0.61 ±0.05  2.82* ±0.46  3.42 ±0.49  4.30 ±0.05  36.1 ±2.07  0.97 ±0.12  3.74** ±0.47  4.70* ±0.54  2  * = p < 0.05  TABLE I I :  p < 0.01  E f f e c t o f i n t r a v e n o u s E p r o s t a g l a n d i n s on A l c i a n Blue b i n d i n g , volume s e c r e t e d and a c i d o u t p u t i n the c l o s e d r a t stomach over 3 hours (Mean ± S.E.).  33  A l l these i n c r e a s e s were h i g h l y s i g n i f i c a n t  (p < 0.01).  Intravenous  a d m i n i s t r a t i o n however d i d not cause a s i g n i f i c a n t i n c r e a s e i n the volume of f l u i d i n the stomach. highly significant v e n o u s l y 16DM  T o p i c a l a p p l i c a t i o n o f each p r o s t a g l a n d i n caused a  (p < 0.01)  and PGE  2  r e d u c t i o n i n a c i d output.  When g i v e n i n t r a  had not e f f e c t on a c i d output, but 15M  i n c r e a s e i n a c i d output t h a t j u s t reached s i g n i f i c a n c e  Histamine produced  (p < 0.05)  i n volume  v a r i a b l e between the i n d i v i d u a l animals a t  t h i s dose and the i n c r e a s e i n a c i d output was significant  i n j e c t i o n s of  a s i g n i f i c a n t i n c r e a s e (p < 0.05)  s e c r e t e d , but the a c i d output was  an  (p < 0.05).  T a b l e I I I shows the r e s u l t s of r e p e a t e d subcutaneous histamine.  caused  not s i g n i f i c a n t .  There was  r e d u c t i o n i n A l c i a n Blue bound t o the mucosa, but  a no  a l t e r a t i o n i n t h a t bound t o the g a s t r i c c o n t e n t s , or the t o t a l amount bound. U l c e r s d i d not develop i n any o f the stomachs.  T a b l e IV shows the degree r a t plasma.  In two  bound p e r ml. o f  o f b i n d i n g o f A l c i a n Blue t h a t o c c u r r e d i n  specimens o f p o o l e d plasma 0.14  plasma.  mg.  A l c i a n Blue  was  EXPERIMENT  NO.  VOLUME i n ml.  ACID OUTPUT yeq H /3 Hr  ALCIAN BLUE BOUND ( i nmg.) MUCOSA  CONTENTS  TOTAL  CONTROL  5  4.14 ±0.01  147.34 ±23.38  0.51 ±0.11  0.45 ±0.06  0.96 ±0.16  HISTAMINE S.C. 6 mg/Kg/Hr  5  4.80* ±0.34  246.84 ±95.03  0.26* ±0.04  0.49 ±0.06  . 0.75 ±0.09  p < 0.05  TABLE I I I :  E f f e c t o f subcutaneous h i s t a m i n e on A l c i a n B l u e b i n d i n g , volume s e c r e t e d and a c i d output i n the c l o s e d r a t stomach o v e r 3 hours (Mean ± S.E.).  PLASMA A  PLASMA B  BLANK  Absorbance  1.0  1.0  1.1  mg AB/5 ml.  0.75  0.75  0.82  Correction for Dilution  1.50  1.50  1.64  mg. AB p p t .  0.14  0.14  TABLE IV:  A l c i a n Blue b i n d i n g by r a t plasma.  36  A STUDY OF THE EFFECT OF THE E  PROSTAGLANDINS ON NONPARIETAL CELL SECRETION  IN CANINE HEIDENHAIN POUCHES (EXPERIMENT 2)  M a t e r i a l and Methods  (i)  P r e p a r a t i o n o f the Animals; s i x female mongrel  The  study was  c a r r i e d out i n a t o t a l of  dogs weighing a p p r o x i m a t e l y 20 Kg.,  b e i n g used i n each s e t o f experiments.  four dogs  Each dog underwent a  laparotomy a t which an antrectomy and g a s t r o d u o d e n a l anastomosis were performed and a Heidenhain pouch p r e p a r e d . the  s u r f a c e through a wide bore m e t a l c a n n u l a .  The pouch opened t o The dogs were  a l l o w e d f o u r weeks t o r e c o v e r from s u r g e r y b e f o r e any t e s t s were performed.  (ii)  C h a r a c t e r i s t i c s o f the Model:  In t h i s model the Heidenhain pouch  should not s e c r e t e a c i d except i n response t o an exogenous s t i m u l u s . Each dog was  t e s t e d t o demonstrate  firstly  t h a t the pouch  respond t o an i n t r a m u s c u l a r dose o f p e n t a g a s t r i n by a c i d  could secretion,  and s e c o n d l y t h a t f o l l o w i n g t h r e e hours p e r f u s i o n w i t h normal no a c i d was  (iii)  saline  s e c r e t e d i n t o the p e r f u s a t e .  The P e r f u s i o n System: system i l l u s t r a t e d  P e r f u s i o n s t u d i e s were performed u s i n g a  s c h e m a t i c a l l y i n F i g u r e 5.  The pouches  filled  by g r a v i t y i n f u s i o n from a r e s e r v o i r s e t a t the h e i g h t o f the pouch, to a v o i d d i s t e n s i o n .  The p e r f u s a t e e n t e r e d a t the bottom and  left  from the t o p and t h e r e b y a t t a i n e d maximum c o n t a c t w i t h the mucosa. The p e r i s t a l t i c pump was p l a c e d on the w i t h d r a w a l l i n e t o r e t u r n the  37  FIGURE 5:  I l l u s t r a t e s the p e r f u s i o n system used i n the c a n i n e H e i d e n h a i n pouches.  38  f l u i d t o t h e r e s e r v o i r and a sampling t a p a l l o w e d r e g u l a r samples t o be t a k e n .  P r i o r t o each experiment the dogs were f a s t e d f o r 18  hours and d u r i n g t h e experiment stood Pavlov t a b l e .  The pouches were p e r f u s e d  60 m l . o f a s o l u t i o n t h a t c o n t a i n e d ethylene  f o r three hours w i t h  5 mEq/L l i t h i u m , 5 gm/L p o l y  g l y c o l (PEG) as a volume marker and was made i s o s m o t i c a t  300 mOsm/L w i t h NaCl.  Samples  i n t e r v a l s and were a n a l y s e d  (iv)  c o m f o r t a b l y supported on a  (3.5 ml.) were taken a t 30 minute  + + + f o r Na , L i , K , CI , HCO^ and PEG.  Analysis  1)  Sodium, L i t h i u m  and. Potassium:  These i o n s were a n a l y s e d  by  flame photometry u s i n g the C o r n i n g Flame Photometer. 2)  Chloride:  3)  Bicarbonate: One  T h i s i o n was measured on a C o r n i n g c h l o r i d e meter. T h i s was measured by the method o f back t i t r a t i o n .  m i l l i l i t e r o f t h e sample was added t o 0.5 ml. o f 0.1 N H C l ,  heated t o d r i v e o f f t h e CO^, d i l u t e d w i t h 10 m l . d i s t i l l e d water and t i t r a t e d a g a i n s t  0.1 N sodium h y d r o x i d e u s i n g an  automatic t i t r i m e t e r (Radiometer Copenhagen). 4)  PEG:  The PEG c o n c e n t r a t i o n  was measured by the method o f  58 Malawer and P o w e l l  which i s a m o d i f i c a t i o n o f the t u r b i m e t r i c  method o f a n a l y s i s .  The t u r b i m e t r i c method i s based on the  c r e a t i o n o f an o i l - i n - w a t e r emulsion o f t h e water s o l u b l e PEG  when t r i c h l o r o a c e t i c a c i d  (TCA) i s added.  In t h i s method  - 59 d e s c r i b e d by Hyden plateau  t h e emulsion l a c k s s t a b i l i t y and the  o f maximum t u r b i d i t y i s s h o r t l i v e d so t h a t p r e c i s e  timing i s required  from t h e a d d i t i o n o f the TCA reagent  until  39  the o p t i c a l d e n s i t y i s r e a d .  The i n s t a b i l i t y i n Hyden's method  r e s u l t s from t h e f a c t t h a t i n t h e c o n c e n t r a t i o n used the droplets coalesce.  Coalescence can be p r e v e n t e d  by t h e a d d i t i o n  of a e m u l s i f y i n g agent which c a n e n t e r t h e o i l - w a t e r i n t e r f a c e and produce a f i l m around t h e d r o p l e t s . agent.  Gum a r a b i c i s such an  The a d d i t i o n o f gum a r a b i c i s t h e b a s i s o f Malawer and  P o w e l l ' s m o d i f i c a t i o n and g i v e s a s t a b l e and p r o l o n g e d  peak o f  maximum t u r b i d i t y which makes p r e c i s e t i m i n g unnecessary and provides  a l i n e a r PEG c o n c e n t r a t i o n - o p t i c a l d e n s i t y r e l a t i o n s h i p  over t h e range o f PEG c o n c e n t r a t i o n used i n t h i s experiment which was  Group I :  500-300 mg/100 ml ( F i g u r e 6 ) .  The E f f e c t o f T o p i c a l A p p l i c a t i o n o f t h e P r o s t a g l a n d i n s :  I n the  c o n t r o l s t u d i e s the pouches were p e r f u s e d w i t h t h e l i t h i u m / s a l i n e / P E G s o l u t i o n alone.  In the experimental  s t u d i e s t h e p r o s t a g l a n d i n s were added  to the perfusate  i n the f o l l o w i n g c o n c e n t r a t i o n s :  15M and 16DM, 10 yg/ml;  PGE , 100 yg/ml. 2  Group I I : these  The. E f f e c t o f Intravenous A d m i n i s t r a t i o n o f P r o s t a g l a n d i n s :  s t u d i e s t h e pouches were p e r f u s e d  solution.  e x c l u s i v e l y w i t h the l i t h i u m / s a l i n e / P E G  In t h e c o n t r o l s t u d i e s 25 m l . normal s a l i n e was g i v e n  each hour.  In t h e e x p e r i m e n t a l  In  s t u d i e s t h e p r o s t a g l a n d i n s were  intravenously administered  i n 75 ml. normal s a l i n e a t a r a t e o f 0.6 yg/Kg/hour f o r 15M and 16DM and 0.6 mg/Kg/hour f o r PGE . 2  These c o n c e n t r a t i o n s previous  and i n f u s i o n r a t e s c o r r e s p o n d  studies o f the permeability e f f e c t s .  t o those used i n  The c o n t r o l experiments and  each o f the p r o s t a g l a n d i n experiments were performed twice  i n each dog.  0.5  r  1  0  I  100  _L_ 200  1  300  I I 400  500  I 600  1  700  PEG mg/100 ml  FIGURE 6:  A r e p r e s e n t a t i v e standard for polyethylene g l y c o l .  curve  800  41  C a l c u l a t i o n o f Data:  Net i o n f l u x e s  (NIF) and p e r m e a b i l i t y f a c t o r s (K) were  c a l c u l a t e d f o r each i o n from t h e f o l l o w i n g  equations:  Vo = V i (PEGi)/(PEGo) VI =  (Vo - SV)(PEGo/PEGi)  Vj = ( V j - i - SV) (PEGj/PEGj-1) NIF  = V j C j - (Vj-1 - SV) C j - 1 where V = volume o f p e r f u s a t e C = concentration of i o n PEG = c o n c e n t r a t i o n o f PEG SV = sample volume i  = i n s t i l l e d solution  o = z e r o time s o l u t i o n .  F o r each i o n s i x 30-minute f l u x d e t e r m i n a t i o n s experiment was t a k e n as the mean o f the l a s t  were made, and t h e NIF f o r the  five  values.  P e r m e a b i l i t y f a c t o r s f o r each i o n were c a l c u l a t e d from t h e formula:  K (ml/30 minute) =  n  e  t  ^ & "»i™tes) 1/2(Cj - Cj-1) (yeq/ml) i  o  n  f  l  u  X  e  3  0  S i x p e r m e a b i l i t y f a c t o r s were c a l c u l a t e d f o r each i o n c o r r e s p o n d i n g s i x 30-minute p e r i o d s .  t o the  The p e r m e a b i l i t y f a c t o r f o r the experiment was taken 55  as t h e mean o f t h e l a s t f i v e v a l u e s .  F o r each c o n c e n t r a t i o n o r dose o f each  p r o s t a g l a n d i n s e i g h t s e t s o f NIF and K v a l u e s were a v a i l a b l e f o r each i o n . The  r e s u l t s a r e expressed  as t h e mean and SE o f these  eight  values.  42  S t a t i s t i c a l Analysis:  The  s t a t i s t i c a l s i g n i f i c a n c e o f any d i f f e r e n c e  the c o n t r o l and e x p e r i m e n t a l v a l u e s was paired  values.  a s s e s s e d u s i n g Student's  between  t-test for  43 Results  The volume s e c r e t e d and t h e b i c a r b o n a t e output  f o r the t o p i c a l  appli  c a t i o n o f t h e p r o s t a g l a n d i n s i s shown i n T a b l e V and f o r i n t r a v e n o u s a d m i n i s t r a t i o n i n Table V I .  When g i v e n by e i t h e r r o u t e 16DM caused  a highly significant  (p < 0.005)  i n c r e a s e i n t h e volume s e c r e t e d over t h e t h r e e hour p e r i o d , i n each b e i n g almost double  15M  the amount produced i n the c o n t r o l  experiments.  and PGE^ g i v e n by e i t h e r r o u t e d i d n o t cause a s i g n i f i c a n t  i n t h e volume o f f l u i d produced.  i n b i c a r b o n a t e s e c r e t i o n over t h e t h r e e hour p e r i o d . caused  a highly significant  The  (p < 0.005) i n c r e a s e  When a p p l i e d t o p i c a l l y  (p < 0.01) i n c r e a s e i n b i c a r b o n a t e  but had no e f f e c t when g i v e n i n t r a v e n o u s l y . s e c r e t i o n when g i v e n by e i t h e r  alteration  I n b o t h groups the i n c r e a s e i n f l u i d  produced by 16DM was a s s o c i a t e d w i t h a h i g h l y s i g n i f i c a n t  15M  case  output  PGE^ had no e f f e c t on b i c a r b o n a t e  route.  e f f e c t o f t o p i c a l a p p l i c a t i o n o f the three p r o s t a g l a n d i n s on the  f o u r i o n s measured i s shown i n T a b l e s V I I and V I I I , T a b l e V I I showing the net i o n f l u x  16DM Na  +  (NIF) f o r each i o n and T a b l e V I I I t h e p e r m e a b i l i t y f a c t o r ( K ) .  caused  and CI  a h i g h l y s i g n i f i c a n t i n c r e a s e (p < 0.0005) i n the NIF o f  but d i d not a l t e r the L i  +  flux.  These a l t e r a t i o n s i n NIF a r e  a l s o r e f l e c t e d i n t h e changes i n t h e p e r m e a b i l i t y f a c t o r s o f these and  the p e r m e a b i l i t y f a c t o r f o r K  (p < 0.05).  +  was a l s o s i g n i f i c a n t l y i n c r e a s e d  15M and PGE^ were w i t h o u t  f a c t o r s o f a l l the i o n s .  ions  e f f e c t on NIF and p e r m e a b i l i t y  NO.  VOLUME PRODUCED ml/3 hours  HCO yEq/3 hours  CONTROL  18.16 ±3.31  121.99 ±31.96  15M 10 yg/ml  18.42 ±1.39  231.15* ±23.93  16DM 10 yg/ml  37.68** ±3.42  PGE 100 yg/ml  22.30 ±2.65  = p < 0.01  TABLE V:  483.37** ±110.99 55.95 ±22.79  p < 0.005  Effect of topical E prostaglandins on volume and b i c a r b o n a t e s e c r e t i o n from H e i d e n h a i n pouch (Mean ± S.E.).  NO.  VOLUME PRODUCED ml/3 hours  HCO uEq/3 hours  CONTROL  13.43 ±2.01  65.91 ±18.52  15M  11.91 ±1.01  30.13 ±10.11  6.6 yg/Kg/Hr 16DM 0.6 yg/Kg/Hr  24.47**' ±1.60  317.78** ±66.27  PGE 0.6 mg/Kg/Hr  12.10 ±1.22  62.37 ±31.88  2  ** = p < 0.005  TABLE V I : E f f e c t o f i n t r a v e n o u s E p r o s t a g l a n d i n s on volume and b i c a r b o n a t e s e c r e t i o n from Heidenhain pouch (Mean ± S.E.)  46  NO.  •+  Cl  Na  Li  +  K  +  CONTROL  8  119.60 ±56.30  -3.22 ±0.80  161.74 ±58.05  26.94 ±2.47  15M 10 yg/ml  8  125.50 ±29.84  -1.46 ±1.08  229.79 ±28.77  21.09 ±2.79  16DM 10 yg/ml  8  553.28** ±87.38  -0.90 ±1.56  666.42** ±87.57  33.48 ±3.27  PGE 100 yg/ml  8  236.48 ±82.85  -3.14 ±1.15  267.76 ±54.22  30.72 ±6.37  2  ** = p < 0.0005  TABLE V I I :  E f f e c t o f t o p i c a l E p r o s t a g l a n d i n s on n e t i o n f l u x e s (yeq/30 minutes) from H e i d e n h a i n pouches (Mean ± S.E.) 2  NO.  Cl  .+ Ll  Na  CONTROL  8  0.80 ±0.38  -0.82 ±0.17  1.08 ±0.38  14.88 ±1.73  15M 10 yg/ml  8  0.85 ±0.17  -0.40 ±0.28  1.65 ±0.20  15.86 ±0.80  16DM 10 yg/ml  8  4.02** ±0.64  -0.49 ±0.53  4.76** ±0.61  19.06* ±1.36  PGE 100 yg/ml  8  1.50 ±0.50  -0.93 ±0.34  1.86 ±0.37  18.53 ±1.84  * = p < 0.05  TABLE V I I I :  +  K  +  ** = p < 0.0005  E f f e c t o f t o p i c a l E p r o s t a g l a n d i n on p e r m e a b i l i t y f a c t o r s K (ml/minute) (Mean ± S.E.). 2  48  The  effect  i n Tables K  of intravenous  IX and X, Table  a d m i n i s t r a t i o n o f the p r o s t a g l a n d i n s  i s shown  IX showing the NIF f o r each i o n and T a b l e  X the  factors.  The  e f f e c t o f 16DM on N a  applied t o p i c a l l y causing NIF,  +  and C l  a higly  significant  and i n a d d i t i o n a s i g n i f i c a n t  However the NIF o f L i  +  i s similar  i n t r a v e n o u s l y as when  (p < 0.0005) i n c r e a s e i n  (p < 0.05) i n c r e a s e i n NIF o f K . +  was s i g n i f i c a n t l y  (p < 0.05) reduced.  15M caused a r e d u c t i o n i n the NIF o f N a  +  and C l , t h e r e b e i n g  l o s s o f these i o n s from the pouch d u r i n g the p e r f u s i o n p e r i o d . in Na  +  fluxes.  f l u x was s i g n i f i c a n t Prostaglandin  Similar alterations  3  the L i  +  or K  factors.  16DM  (p < 0.0005) i n c r e a s e i n K + and K - and * Na Cl  (p < 0.05) r e d u c t i o n i n K .+. La With 15M the r e d u c t i o n s  The i n c r e a s e i n K + was n o t K  i n K + and K - were Na Cl  (p < 0.05), but 15M was w i t h o u t e f f e c t on K .+ and K + . Li JC e f f e c t on the p e r m e a b i l i t y  The r e d u c t i o n  on the NIF o f a l l the i o n s .  were produced i n the p e r m e a b i l i t y  1  significant.  15M d i d n o t a f f e c t  was w i t h o u t e f f e c t  caused a h i g h l y s i g n i f i c a n t ^ ^ a significant  (p < 0.05).  a net  factors.  significant  PGE  was without 2  +  +  +  NO.  Cl  CONTROL  8  31.74 ±34.55  -5.25 ±1.02  49.91 ±37.20  17.16 ±1.61  15M 0.6  8  -31.78 ±19.12  -4.85 ±0.86  -40.35* ±18.03  17.34 ±3.76  16DM 0.6 yg/Kg/Hr  8  363.21** ±41.28  -2.48* ±0.74  421.85** ±66.79  24.98* ±1.85  PGE 0.6 mg/Kg/Hr  8  39.66 ±28.46  -4.66 ±0.88  30.73 ±27.80  20.34 ±2.09  yg/Kg/Hr  * = p < 0.05  TABLE IX:  L i  +  Na  K  ** = p < 0.0005  E f f e c t o f i n t r a v e n o u s E^ p r o s t a g l a n d i n s on n e t i o n f l u x e s (yeq/30 minutes) from H e i d e n h a i n pouches (Mean ± S.E.)  NO.  Cl  L i  +  Na  +  +  CONTROL  8  0.23 ±0.24  -1.39 ±0.28  15M 0.6 yg/Kg/Hr  8  -0.22* ±0.10  -1.30 ±0.22  -0.29* ±0.10  13.11 ±2.38  16DM 0.6 yg/Kg/Hr  8  2.55** ±0.28  -0.73* ±0.17  3.02** ±0.43  17.27 ±1.70  PGE 0.6 yg/Kg/Hr  8  0.28 ±0.20  -1.19 ±0.22  0.22 ±0.17  16.29 ±1.03  2  * = p < 0.05  TABLE X:  . 0.32 ±0.26  K  14.76 ±1.21  ** = p < 0.0005  E f f e c t o f i n t r a v e n o u s E p r o s t a g l a n d i n s on p e r m e a b i l i t y f a c t o r s K (ml/minute) (Mean ± S.E.)  51  THE EFFECT OF E  2  PROSTAGLANDINS ON THE  MUCOSAL BARRIER DAMAGE  1.  REVERSAL OF ESTABLISHED GASTRIC  (EXPERIMENT 3)  P r e p a r a t i o n and V a l i d a t i o n o f a S u i t a b l e  M a t e r i a l and Methods:  Model  The experiments were c a r r i e d out on f i v e  tomized dogs w i t h H e i d e n h a i n pouches.  antrec  The p e r f u s i o n system used  was  as d e s c r i b e d and i l l u s t r a t e d i n the p r e v i o u s c h a p t e r but v a r i o u s m o d i f i c a t i o n s i n the method were i n t r o d u c e d . p e r i o d was  The t h r e e hour p e r f u s i o n  d i v i d e d i n t o t h r e e s e p a r a t e one hour p e r i o d s , samples were  t a k e n a t 10 minute i n t e r v a l s and the p e r f u s i n g s o l u t i o n was the  end of each hour.  In t h i s way  p e r m e a b i l i t y f a c t o r f o r each hour.  changed a t  i t was p o s s i b l e t o c a l c u l a t e t h e The r e s u l t s f o r the f i r s t two  hours  were averaged.  C o n t r o l experiments were performed i n which the pouches were p e r f u s e d f o r each o f t h e t h r e e one hour p e r i o d s w i t h an a c i d / s a l i n e s o l u t i o n c o n t a i n i n g 120 mEq/L hydrogen i o n , 5 gm/L marker  PEG  as a volume  and made i s o s m o t i c a t 300 mOsm/L w i t h sodium c h l o r i d e .  In  subsequent experiments damage o f the g a s t r i c mucosal b a r r i e r  was  produced by p e r f u s i n g the pouches d u r i n g the f i r s t two hours  (Damage  P e r i o d ) w i t h a c i d s a l i n e s o l u t i o n s c o n t a i n i n g 20 mM the  t h i r d hour  used.  aspirin.  (Recovery P e r i o d ) o n l y an a c i d / s a l i n e p e r f u s a t e  ( F i g u r e 7)  During was  THE EXPERIMENTAL MODEL FIRST TWO HOURS (DAMAGE PERIOD)  POUCH PERFUSED WITH HCl AND ASA  THIRD HOUR (RECOVERY PERIOD)  POUCH PERFUSED WITH HCl ALONE  FIGURE 7:  I l l u s t r a t i o n o f t h e e x p e r i m e n t a l model used t o t e s t the e f f e c t o f v a r i o u s d r u g s on e s t a b l i s h e d g a s t r i c mucosal b a r r i e r damage.  53  Analysis:  The f o l l o w i n g a n a l y s e s were c a r r i e d o u t on each  10-minute  sample, by the methods p r e v i o u s l y d e s c r i b e d . 1)  Hydrogen Ion  2)  Sodium and Potassium  3)  Chloride  4)  Polyethylene  Glycol  C a l c u l a t i o n o f Data:  The r e s u l t s a r e e x p r e s s e d as p e r m e a b i l i t y f a c t o r s  (K) f o r each i o n which were c a l c u l a t e d from each experiment from the r e g r e s s i o n l i n e o f t h e l o g o f the c o n c e n t r a t i o n o f the i o n a g a i n s t time.  The s l o p e o f the r e g r e s s i o n l i n e i s m u l t i p l i e d by the average  volume o f the p e r f u s a t e t o g i v e the K v a l u e s .  Results:  The a d d i t i o n o f 20 mM a s p i r i n t o the p e r f u s a t e  significant  caused a  (p < 0.005) i n c r e a s e i n K + and K + d u r i n g the Damage H Na  P e r i o d , i n d i c a t i n g damage t o the g a s t r i c mucosal b a r r i e r  (Table X I ) .  In the Recovery P e r i o d when o n l y an a c i d s a l i n e p e r f u s a t e was used the pouches t h a t had been p r e v i o u s l y p e r f u s e d w i t h the a c i d / s a l i n e and a s p i r i n e x h i b i t e d e v i d e n c e o f c o n t i n u i n g g a s t r i c mucosal b a r r i e r damage as b o t h K + and K + remained s i g n i f i c a n t l y H Na the c o n t r o l l e v e l s .  (Table 11)  (p < 0.05) e l e v a t e d above  I n the pouches exposed t o a s p i r i n  was no s i g n i f i c a n t d i f f e r e n c e between the K + and K + v a l u e s H Na Damage and Recovery P e r i o d s .  Conclusions:  T h i s model p r o v i d e s  i n the  a p e r i o d o f one hour i n which  gastric  mucosal b a r r i e r damage p e r s i s t s d e s p i t e w i t h d r a w a l o f the damaging agent.  I n subsequent experiments t h i s model was used.  there  DAMAGE PERIOD NIF- ueq/minute PERFUSING SOLUTION  NO  CONTROL  ACID SALINE  20  14.39 ±1.47  DAMAGE  ACID SALINE + 20 mM ASA  20  22.50** -16.64** ±2.50 ±2.54  EXPERIMENT  Na  H  K Na  -2.49 ±1.44  H  0.30 ±0.03  -0.13 ±0.01  0.42** ±0.30  -0.29** ±0.04  RECOVERY PERIOD CONTROL  ACID SALINE  10  14.27 ±2.08  -0.56 ±2.53  0.27 ±0.03  -0.12 ±0.02  DAMAGE  ACID SALINE  10  20.30 ±3.28  -9.20* ±3.51  0.41* ±0.05  -0.20* ±0.04  = p < 0.05  TABLE X I :  p < 0.005  E f f e c t o f 20 mM a s p i r i n d u r i n g the Damage P e r i o d on n e t i o n f l u x _£NIF peq/minute) and p e r m e a b i l i t y f a c t o r (K) f o r Na and H (Mean ± S.E.).  55 2.  Study o f the E f f e c t s o f PGE , 15M and Metiamide on E s t a b l i s h e d G a s t r i c 2  Mucosal B a r r i e r Damage  M a t e r i a l and Methods:  Using  the model j u s t d e s c r i b e d and v a l i d a t e d  experiments were performed t o study the e f f e c t o f t o p i c a l P G E and  intravenous  Group I : PGE  2  p  2  and 15M  G E ' 15M and metiamide. 2  The E f f e c t o f T o p i c a l A p p l i c a t i o n s o f the P r o s t a g l a n d i n s :  and 15M were added t o the a c i d s a l i n e p e r f u s a t e d u r i n g the Recovery  P e r i o d , PGE^ i n a c o n c e n t r a t i o n o f 100 yg/ml and 15M i n a c o n c e n t r a t i o n of 10 yg/ml.  Group I I :  The E f f e c t o f Intravenous A d m i n i s t r a t i o n o f the P r o s t a g l a n d i n s :  PGE^ and 15M were g i v e n by i n t r a v e n o u s  i n f u s i o n i n 25 m l . normal s a l i n e  d u r i n g t h e Recovery P e r i o d - PGE^ a t a r a t e o f 0.3 mg/Kg/hour, 15M a t a r a t e o f 0.6 yg/Kg/hour.  Group I I I :  The E f f e c t o f Intravenous A d m i n i s t r a t i o n o f Metiamide:  Metiamide was g i v e n a t a r a t e o f 3 mg/Kg/hour. above t h e ED  50  T h i s dose o f metiamide i s  f o r the i n h i b i t i o n o f s t i m u l a t e d a c i d s e c r e t i o n i n a canine  Heidenhain pouch^^ and i s comparable i n i t s a n t i s e c r e t o r y e f f e c t w i t h the doses o f the p r o s t a g l a n d i n s  used.  56  Results  In T a b l e X I I t h e amount o f t h e damage produced d u r i n g t h e Damage P e r i o d i n a l l t h e experiments i s shown i n terms o f p e r m e a b i l i t y f a c t o r s K and K and t h e n e t i o n f l u x o f H H Na  +  and N a . +  The experiments i n which the e f f e c t o f t o p i c a l 15M was t e s t e d K +, K +, and H H Na  +  f l u x i n t h e Damage P e r i o d were l e s s than those i n t h e  v a l i d a t i o n experiments, i n d i c a t i n g t h a t t h e degree o f damage was o f a l e s s e r degree.  I n the experiments i n which t h e agents were g i v e n  intravenously the H  +  f l u x was s i g n i f i c a n t l y  15M experiment and the N a  +  flux  (p < 0.005) reduced i n the  (p < 0.05) i n the metiamide  experiment,  but t h e r e was no d i f f e r e n c e i n the p e r m e a b i l i t y f a c t o r s , and i t i s t h e r e f o r e c o n s i d e r e d t h a t the amount o f damage c a r r i e d over i n t o t h e Recovery P e r i o d was comparable that f o r t o p i c a l  i n a l l the e x p e r i m e n t a l groups, e x c e p t  15M.  T a b l e X I I shows t h e e f f e c t o f t o p i c a l PGE 2. K N a  + v a l u e s and NIF d u r i n g t h e Recovery P e r i o d .  and 15M on K + and H There was no s i g n i f i  cant d i f f e r e n c e between the K v a l u e s o r t h e NIF when no treatment was g i v e n and when PGE,, was a p p l i e d t o p i c a l l y .  T o p i c a l 15M d i d n o t cause a  s i g n i f i c a n t r e d u c t i o n i n K + o r t h e N a f l u x , b u t K + was reduced H ' Na (p < 0.005) as was the H f l u x (p < 0.05). However as t h e r e was no +  +  d i f f e r e n c e between the K + o r H Na  +  f l u x v a l u e s i n the Damage and  Recovery P e r i o d f o r the t o p i c a l 15M experiments, the low v a l u e s i n the Recovery P e r i o d can n o t be taken t o i n d i c a t e any r e v e r s a l o f damage.  DAMAGE PERIOD NIF ueq/minute EXPERIMENT  NO.  No Treatment  20  22.50 ±2.50  -16.64 ±2.54  0.42 ±0.03  -0.29 ±0.04  Top. P G E  18  19.28 ±1.85  -11.35 ±1.83  0.35 ±0.04  -0.25 ±0.01  16  17.08 ±2.49  0.24** ±0.03  -0.21* ±0.02  24  21.20 ±1.62  0.43 ±0.01  -0.27 ±0.03  I.V. 15M  18  20.44 ±2.42  0.35 ±0.05  -0.23 ±0.03  I.V. Metiamide  12  17.09* ±1.60  0.36 ±0.03  -0.22 ±0.02  2  Top. 15M  I.V. P G E  2  Na  +  p < 0.05  TABLE X I I :  H  K  +  -7.17**. ±1.86 -13.44 ±2.72 -4.63** ±3.53 -11.53 ±1.80  Na  +  H  +  ** = p < 0.005  Comparison o f the a l t e r a t i o n i n NIF (yeq/minute) and K o c c u r r i n g i n the Damage P e r i o d i n a l l the groups i n which a s p i r i n damage was produced (Mean ± S.E.).  RECOVERY PERIOD PERFUSING SOLUTION DAMAGE  RECOVERY  TREATMENT DURING R.P.  Na Acid Saline + ASA 20 mM  Acid  Saline  Acid Saline + ASA 20 mM  Acid  Saline  Top. PGE„ 100 yg/ml  Acid Saline + ASA 20 mM  Acid  Saline  Top. 15M 10 yg/ml  * = p <  TABLE X I I I  Nil  K  NIF yeq/minute NO. H  Na  H  10  20.30 ±3.28  -9.20 ±3.51  0.41 ±0.05  -0.21 ±0.04  10  23.80 ±3.69  -3. 41 ±1. 86  0.34 ±0.06  -0.22 ±0.03  17.68 ±2.95  -0.39* ±3.48  0.22** ±0.03  -0.17 ±0.03  0.05  E f f e c t o f treatment w i t h t o p i c a l PGE NIF and K (Mean ± S.E.).  p < 0.005  and 15M on e s t a b l i s h e d GMB  damage  59  T a b l e XIV shows the e f f e c t agents on K + and K  + i n t h e Recovery P e r i o d .  PGE  (p < 0.005) r e d u c t i o n i n K + H  15M a s i g n i f i c a n t  caused a h i g h l y 2  Ncl  ri  significant  o f the t h r e e i n t r a v e n o u s l y a d m i n i s t e r e d  r e d u c t i o n (p < 0.025).  and K  + d u r i n g t h i s p e r i o d and Na  Metiamide on the o t h e r hand d i d  not a l t e r the p e r m e a b i l i t y f a c t o r s , t h e r e b e i n g no s i g n i f i c a n t d i f f e r e n c e between K + H  and K  + when treatment Na  treatment.  The d a t a f o r the NIF o f N a  data, there being a s i g n i f i c a n t but no change w i t h metiamide.  w i t h metiamide was compared w i t h no +  supports  the p e r m e a b i l i t y f a c t o r  (p < 0.025) r e d u c t i o n w i t h PGE^ and 15M The NIF o f H  +  was reduced  15M b u t these v a l u e s d i d n o t q u i t e r e a c h s i g n i f i c a n c e . not a l t e r the NIF o f H . +  by PGE  2  and  Metiamide d i d  RECOVERY PERIOD PERFUSING SOLUTION DAMAGE  RECOVERY  TREATMENT DURING R.P.  NIF yeq/minute Na  Acid Saline + ASA 20 mM  Acid  Saline  Acid Saline + ASA 20mM  Acid  Saline  I.V. PGE 0.3 mg/Kg/Hr  Acid Saline + ASA 20 mM  Acid  Saline  I.V. 15M 0.6 yg/Kg/Hr  Acid Saline + ASA 20 mM  Acid Saline  IV Metiamide 3 mg/Kg/Hr  Nil  * = p < 0.025  TABLE XIV:  K  NO. H  Na  +  H  10  20.30 ±3.28  -9.20 ±3.51  0.41 ±0.05  -0.21 ±0.04  12  10.52* ±1.58  -2.14 ±1.88  0.23** ±0.04  -0.10** ±0.01  12.13* ±1.98  -1.23 ±3.90  0.23* ±0.05  -0.10* ±0.03  16.95 ±1.75  -5.97 ±1.39  0.37 ±0.03  -0.17 ±0.02  6  ** = p < 0.005  E f f e c t o f t r e a t m e n t w i t h i n t r a v e n o u s PGE , 15M and Metiamide on e s t a b l i s h e d GMB damage. NIF and K (Mean ± S.E. 2  o  61  DISCUSSION  The  prostaglandins  have been shown capable o f p r e v e n t i n g  damage t o  the g a s t r i c mucosa by a mechanism which i s unknown b u t which i s n o t r e l a t e d t o t h e i r a c t i o n as i n h i b i t o r s o f a c i d s e c r e t i o n .  Because o f the p o t e n c y o f the E^ p r o s t a g l a n d i n s  as i n h i b i t o r s o f a c i d  s e c r e t i o n , i t was n o t u n t i l t h e s e agents were s t u d i e d i n b a s a l pouch  prepara  t i o n s t h a t i t was a p p r e c i a t e d  t h a t they a l s o had a s e c r e t o r y a c t i o n on  c e l l s i n the g a s t r i c mucosa.  These e f f e c t s on mucus and n o n p a r i e t a l  other  cell  s e c r e t i o n have been s t u d i e d as both e f f e c t s c o u l d be regarded as p r o t e c t i v e i n n a t u r e and may p l a y a p a r t i n t h e p r o t e c t i v e e f f e c t o f t h e p r o s t a g l a n d i n s . T h i s s e c r e t o r y a c t i o n may a l s o be r e s p o n s i b l e f o r the m i s i n t e r p r e t a t i o n o f some p e r m e a b i l i t y  Most p r e v i o u s  data.  s t u d i e s have measured o n l y one component  o f g a s t r i c mucus.  The m a j o r i t y have measured f r e e mucus, t h i s b e i n g the e a s i e s t t o c o l l e c t and measure, b u t a t l e a s t two s t u d i e s have measured b a r r i e r mucus.  In t h i s  an attempt was made t o measure the e f f e c t o f the p r o s t a g l a n d i n s  i n both  study  fractions.  The r e s u l t s i n d i c a t e t h a t when given t o p i c a l l y and i n t r a v e n o u s l y the prostaglandins  cause an i n c r e a s e i n the f r e e f r a c t i o n o f mucus b u t a r e  without e f f e c t on the b a r r i e r f r a c t i o n , but t h e r e was the i n d i v i d u a l agents.  Prostaglandin  some v a r i a t i o n w i t h  E^ produced the same e f f e c t s b o t h  t o p i c a l l y and i n t r a v e n o u s l y b e i n g without e f f e c t on the b a r r i e r mucus b u t causing  an i n c r e a s e i n the f r e e f r a c t i o n and an o v e r a l l i n c r e a s e i n mucus  62  production. 15M.  T h i s same p a t t e r n was shown by t o p i c a l 16DM and i n t r a v e n o u s 16DM caused a s i m i l a r t r e n d b u t the t o t a l amount o f mucus  Intravenous  produced was n o t s i g i n f i c a n t l y g r e a t e r than  the c o n t r o l s .  The o n l y  results  which d i d n o t f i t t h i s p a t t e r n were those w i t h t o p i c a l 15M i n which t h e r e was no i n c r e a s e i n the t o t a l amount o f mucus produced, b u t t h e r e was a significant f a l l  i n b a r r i e r mucus and a c o r r e s p o n d i n g  increase i n free  mucus s u g g e s t i n g t h a t t h i s agent s t r i p p e d mucus from t h e mucosa so i n c r e a s i n g the f r e e f r a c t i o n w i t h o u t  s t i m u l a t i n g mucus p r o d u c t i o n .  An attempt was  made t o compare the s t i m u l a n t e f f e c t o f the p r o s t a g l a n d i n s w i t h s t i m u l a n t o f g a s t r i c mucus  another  ( h i s t a m i n e ) , but t h i s was n o t s a t i s f a c t o r y  because o f the d i f f e r e n t e f f e c t s o f the s t i m u l a n t s on a c i d s e c r e t i o n . combination  o f p y l o r i c l i g a t i o n and p a r e n t e r a l h i s t a m i n e  the r a t , and i t was f e l t  A  i s ulcergenic i n  t h a t i n the presence o f muosal u l c e r a t i o n A l c i a n  Blue would b i n d t o the areas o f mucosal d e s t r u c t i o n , so g i v i n g f a l s e l y v a l u e s f o r b a r r i e r mucus.  U n f o r t u n a t e l y the dose o f h i s t a m i n e  high  chosen d i d  not produce a s i g n i f i c a n t i n c r e a s e i n a c i d output, b u t i t d i d n o t cause ulcers. in  Histamine caused a r e d u c t i o n i n b a r r i e r mucus b u t no a l t e r a t i o n  f r e e mucus o r the t o t a l amount produced.  The i n c r e a s e i n f r e e mucus  produced by the p r o s t a g l a n d i n s was g r e a t e r than the e f f e c t produced by histamine to  but as t h e dose o f h i s t a m i n e was n o t maximal - i t was n o t p o s s i b l e  draw any c o n c l u s i o n r e g a r d i n g the magnitude o f the response evoked by  the p r o s t a g l a n d i n s .  As dose-response s t u d i e s w i t h t h e p r o s t a g l a n d i n s were  not performed t h e maximal mucus response t o p r o s t a g l a n d i n i s n o t known.  Because the r o l e o f g a s t r i c mucus i s u n c l e a r the i n t e r p r e t a t i o n o f t h i s data i s d i f f i c u l t .  G a s t r i c mucus i s f r e e l y permeable t o hydrogen i o n  and has o n l y minimal b u f f e r i n g c a p a c i t y , and i t p l a y s no p a r t i n the  63  g a s t r i c mucosal b a r r i e r o r i n the n e u t r a l i z a t i o n  of intraluminal  acid.  It  p r o b a b l y a c t s as a l u b r i c a n t on the g a s t r i c mucosa and p r e v e n t s minor degrees o f mechanical damage t o the u n d e r l y i n g c e l l s .  I t i s b a r r i e r mucus  t h e r e f o r e which i s p r o b a b l y the important f r a c t i o n w h i l e f r e e mucus p r o b a b l y r e p r e s e n t s denatured and shed b a r r i e r muucs.  I f f r e s h l y s e c r e t e d mucus  f i r s t appears as b a r r i e r mucus adherent t o the mucosa, and then as a r e s u l t o f the a c t i o n  o f a c i d , p e p s i n and l o c a l enzymes i s broken down and shed as  f r e e mucus, one might e x p e c t an i n c r e a s e i n the b a r r i e r f r a c t i o n i n r e s p o n s e t o a s t i m u l a n t o f mucus s e c r e t i o n .  I f however the b a r r i e r f r a c t i o n s t a y s  more o r l e s s c o n s t a n t then an i n c r e a s e i n the f r e e mucus f r a c t i o n would indicate  that  e x i s t i n g b a r r i e r mucus had been shed and r e p l a c e d by f r e s h l y  s e c r e t e d mucus.  The  p r o s t a g l a n d i n s d i d n o t i n c r e a s e b a r r i e r mucus and a l l e x c e p t 15M  caused no change i n t h i s f r a c t i o n b u t an o v e r a l l i n c r e a s e i n mucus produc tion.  The replacement o f e x i s t i n g b a r r i e r mucus by f r e s h l y s e c r e t e d mucus  which would p e r f o r m i t s f u n c t i o n protective,  more e f f i c i e n t l y c o u l d be r e g a r d e d as  a t l e a s t as f a r as minor mechanical trauma i s concerned.  The  reason f o r t h e r e d u c t i o n i n b a r r i e r mucus caused by t o p i c a l 15M i s n o t c l e a r and may r e p r e s e n t an i n a c c u r a c y i n the method.  The  method o f measurement used i n t h i s study i s p r o b a b l y l e s s  accurate  than many o f the b i o c h e m i c a l methods o f a n a l y s i s , b u t has the advantage both f r a c t i o n s can be measured.  I t was chosen f o r t h i s r e a s o n and i t s  s i m p l i c i t y , on the u n d e r s t a n d i n g t h a t  i f t h e p r o s t a g l a n d i n s were c o n f i r m e d  as s t i m u l a n t s o f mucus p r o d u c t i o n then o t h e r more s o p h i s t i c a t e d c o u l d be a p p l i e d  that  t o the problem i n the f u t u r e .  techniques  64  The  o t h e r i m p o r t a n t f i n d i n g i n t h i s study was  t o p i c a l l y t o the mucosa a l l t h r e e p r o s t a g l a n d i n s volume d e s p i t e a f a l l  i n a c i d output.  s i b l e to measure b i c a r b o n a t e t h a t the f l u i d  s e c r e t e d was  i n h i b i t o r o f a c i d s e c r e t i o n and  caused an i n c r e a s e i n  In these experiments i t was  s e c r e t i o n , but alkaline.  t h a t when a p p l i e d  P  G  E 2  t h e r e was  indirect  impos  evidence  a p p l i e d t o p i c a l l y i s a poor  y e t i n a dose w e l l below the ED  i t caused  50 a g r e a t e r r e d u c t i o n i n a c i d o u t p u t than i t s more p o t e n t I t a l s o caused the l a r g e s t volume i n c r e a s e and r e d u c t i o n i n a c i d output and  methyl analogues.  t h e r e f o r e the  apparent  the unexpected potency c o u l d be due  to  neutra  l i z a t i o n o f the s m a l l amount o f a c i d s e c r e t e d i n t h e s e vagotomised r a t s by the a d d i t i o n a l s e c r e t i o n o f an a l k a l i n e g a s t r i c j u i c e .  There are at l e a s t t h r e e p o s s i b l e e x p l a n a t i o n s effects: blood  f o r these observed  damage t o the g a s t r i c mucosal b a r r i e r , an i n c r e a s e  i n mucosal  flow o r s t i m u l a t i o n o f n o n p a r i e t a l and mucus s e c r e t i n g c e l l s .  Damage to the g a s t r i c mucosal b a r r i e r c o u l d cause an i n c r e a s e i n the f l u i d transudate ouput due 16DM  i n t o the g a s t r i c lumen and  t o back d i f f u s i o n .  has been suspected  However o f the p r o s t a g l a n d i n s  of breaking  e f f e c t of a l t e r a t i o n i n b l o o d  flow may  be more i m p o r t a n t .  s e c r e t i o n remains u n c e r t a i n .  transudate  HCO^  +  ~ a c t i v e l y s e c r e t e HCO^  only other  suggestion.  o r i g i n of n o n p a r i e t a l c e l l c o n t a i n i n g Na ,  studied  the g a s t r i c mucosal b a r r i e r and  experiments i n t h i s t h e s i s r e f u t e t h i s  The  an apparent r e d u c t i o n i n a c i d  and p r o t e i n ,  6 1 , 6 2  The  Is i t a plasma  o r do n o n p a r i e t a l  cells  63 and mucus i n response t o s p e c i f i c s t i m u l i ?  former were t r u e an i n c r e a s e i n mucosal b l o o d  flow accompanied by an  I f the increase  65  in hydrostatic pressure protein.  c o u l d l e a d to an i n c r e a s e d t r a n s u d a t i o n  of f l u i d  and  A l c i a n Blue has been shown not t o b i n d s i g n i f i c a n t l y t o plasma  p r o t e i n and  t h e r e f o r e the measured i n c r e a s e i n A l c i a n B l u e b i n d i n g i n the  g a s t r i c contents  i s not  the g a s t r i c lumen.  s o l e l y due  t o an i n c r e a s e i n the plasma p r o t e i n i n  A l s o i t i s to be expected t h a t the v a s o a c t i v e  of those agents would be more apparent w i t h i n t r a v e n o u s administration.  The  i n c r e a s e s i n mucus p r o d u c t i o n  r a t h e r than t o p i c a l  following  intravenous  a d m i n i s t r a t i o n o c c u r e d i n the absence o f any volume changes and independent o f the s e c r e t i o n o f a l k a l i n e j u i c e .  properites  so must be  This evidence s t r o n g l y  suggests t h a t i n the r a t these agents s t i m u l a t e mucus and n o n p a r i e t a l  cell  secretion.  Further  e v i d e n c e t h a t the  to n o n p a r i e t a l c e l l  i n c r e a s e i n f l u i d i n the r a t stomachs was  s e c r e t i o n was  gained  from the second s e r i e s of experiments,  but these experiments, performed i n dogs, i n d i c a t e t h a t t h e r e may s p e c i e s v a r i a t i o n i n response t o the i n d i v i d u a l agents. 16DM  stimulated nonparietal c e l l  t o p i c a l and  intravenous  In the dog  s e c r e t i o n was  acid free.  double the c o n t r o l volume. i n the amount o f b i c a r b o n a t e  was  In the dogs o n l y  d i d so when g i v e n by b o t h  prostaglandins  In t h i s system o n l y 16DM  Associated with s e c r e t e d and  caused  yEq.  The  on  an  t h i s amounted t o almost  t h i s was  a significant  i n the i n f l u x o f N a  +  the t o t a l i n f l u x o f c a t i o n i n yEq/30 minutes  a p p r o x i m a t e l y 700  the  s t u d i e d i n the p r e s e n c e o f a  f l u i d produced by the pouches, but  Using t o p i c a l 16DM  be some  routes.  nonparietal c e l l  pouch p e r f u s a t e t h a t was i n c r e a s e i n the  s e c r e t i o n but  experiments the e f f e c t of the t h r e e  p e r m e a b i l i t y and  due  t o t a l i n f l u x o f anion  and (Na  increase Cl . +  and  i n yEq/30 minutes  K) +  was  66  553 yEq C l  plus one s i x t h of the bicarbonate output over the three hours,  i . e . 80 yEq/30 minutes, a t o t a l of 633 yEq/30 minutes.  Using intravenous  16DM the corresponding figures are for cation 445 yEq/30 minutes and for anion 416 yEq/30 minutes.  Minor degrees of pouch distension could lead to  the secretion of H and the r e s u l t i n g n e u t r a l i z a t i o n of bicarbonate could +  account f o r the anion d e f i c i t .  The evidence suggests that 16DM stimulates nonparietal c e l l secretion i n the dog, the f l u i d produced being r i c h i n Na and C l +  and containing  some bicarbonate.  15M and PGE^ both t o p i c a l l y and intravenously had no e f f e c t on f l u i d production and PGE^ and intravenous 15M were without e f f e c t on bicarbonate secretion.  Topical 15M however caused a s i g n i f i c a n t increase i n bicarbonate  secretion.  This r e s u l t i s not readily explained but the other values may  be underestimates as a r e s u l t of distension and p a r t i a l n e u t r a l i z a t i o n .  The e f f e c t of the prostaglandins on gastric mucosal permeability was + measured by studying the movement of L i .  + The net e f f l u x of L i from the 55  Heidenhain pouch of antrectomized dogs has been studied by Chung et a l in r e l a t i o n to the net e f f l u x of hydrogen.  In the presence of various  b a r r i e r breakers i t was found that the r a t i o K .+/K + remained unchanged Ll H and i t was concluded that K .+ i s a useful i n d i r e c t measure of mucosal Li permeability. The accuracy of the relationship K .+/K+ has been questioned Li H i n human studies where a variety of uncontrolled factors may i n t e r f e r e , but in the closed perfusion system of a Heidenhain pouch the r e l a t i o n s h i p i s v a l i d and has been confirmed by extensive studies i n t h i s laboratory.  67  All  three prostaglandins  a p p l i e d t o p i c a l l y and  15M  and p r o s t a g l a n d i n  g i v e n i n t r a v e n o u s l y were w i t h o u t e f f e c t on net i o n f l u x o f L i whereas the i n t r a v e n o u s i n NIF  of L i  +  and  K  mucosal b a r r i e r .  a d m i n i s t r a t i o n o f 16DM  +.  +  and  K  T h i s i n d i c a t e s t h a t 16DM  reduction  t i g h t e n s the g a s t r i c  This f i n d i n g i s contrary to that p r e v i o u s l y reported  i s more i n k e e p i n g w i t h the o t h e r recorded  2  +.  Li  caused a s i g n i f i c a n t  E  e f f e c t s of  but  16DM.  48 O'Brien and  Carter  reported  Heidenhain pouches exposed t o 16DM from the pouch.  an i n c r e a s e i n p e r m e a b i l i t y by d i r e c t l y measuring the  They used a system of repeated  canine  l o s s of  instillations  the c o n t i n u o u s p e r f u s i o n system used i n these experiments.  in  H  +  r a t h e r than  In t h e i r  experi  mental system each experiment c o n s i s t e d of s i x 30-minute p e r i o d s .  Periods  and  6 were  2 were c o n t r o l s and  P e r i o d 3 the t e s t p e r i o d ; P e r i o d s  further control periods. w i t h those i n P e r i o d s t h a t the NIF  of H  abnormally low.  +  The  1 and  2, and  i n Periods  Had  n e t i o n f l u x of H  c e l l secretion.  i n Period  from t h e i r data  1 and  2 p r i o r to the  5 and  3 i s compared  (Table XV)  i t can be  a p p l i c a t i o n of 16DM  seen was  the v a l u e been i n the same range as i n t h e i r c o n t r o l  experiments t h e r e would have been no can be a t t a c h e d  +  4,  1  t o the N a  +  No  signficance  f l u x d a t a i n view of the s t i m u l a t i o n o f  T h e i r c l a i m t h a t 16DM  i s based on q u e s t i o n a b l e  significant difference.  increases  nonparietal  g a s t r i c mucosal p e r m e a b i l i t y  data.  However t h i s f i n d i n g d i d r e c e i v e support  from the work o f B o l t o n  and  49 Cohen,  i n which they c l a i m e d  g a s t r i c mucosal b a r r i e r but the i n f u s i o n of the agent.  t h a t not o n l y d i d t o p i c a l 16DM same e f f e c t was  produced by  The method by which t h e i r d a t a was  not a l l o w f o r the p o s s i b i l i t y of a c t i v e n o n p a r i e t a l c e l l  break  the  continuous calculated did  s e c r e t i o n , and  this  H  BACK DIFFUSION  (MEAN AND S.E.)  OUTPUT  PERIOD 3 n=6  CONTROL (basal s o l u t i o n )  -81 ± 46  -85 ± 57  0.47  190 ± 57  134 ± 41  0.40  16 DM 300 yg/20 ml i n pouch (basal s o l u t i o n )  -13 ± 19  187 ± 76  >0.001  132 ± 61  781 ± 64  >0.001  TABLE XV:  PERIODS 1 AND 2 n=12  (MEAN AND S.E.]  PERIODS 1 AND 2 n = 12  EXPERIMENTS  P VALUE  NET Na  Comparision o f i o n i c f l u x e s between c o n t r o l and t e s t p e r i o d s C a r t e r DC, Gut 16: 437-442, 1975.  PERIOD 2 n = 6  P VALUE  (from O'Brien PE,  69  has p r o b a b l y  l e d to erroneous c o n c l u s i o n s .  Mucosal p e r m e a b i l i t y  determined by measuring the slope o f the r e g r e s s i o n l i n e  (K)  f o r the  l o g of  c o n c e n t r a t i o n of each i o n a g a i n s t time, and m u l t i p l y i n g t h i s by the volume of the p e r f u s a t e  d u r i n g the experiment.  was  average  T h i s method o f c a l c u l a t i o n  i s v a l i d o n l y i f the average volumes i n the groups under comparison are same.  I f i n one  the  group the volume i n c r e a s e i s much l a r g e r then the  the  concen  t r a t i o n o f the v a r i o u s i o n s w i l l change not o n l y as a r e s u l t of movement a c r o s s the mucosa but a l s o due accounts f o r the  to a d i l u t i o n a l f a c t o r .  f i n d i n g of B o l t o n and  Cohen and  This e f f e c t  t h e i r data i s c u r r e n t l y  under r e - e v a l u a t i o n by the method used i n t h i s study, which has been d e s c r i b e d .  In t h i s method NIF  and  probably  already  K are c a l c u l a t e d f o r each 30 minute  i n t e r v a l t a k i n g i n t o account the volume changes over t h a t p e r i o d .  Two  conclusions  can be drawn from t h i s study.  F i r s t l y that  s t i m u l a t e s a n o n p a r i e t a l c e l l s e c r e t i o n c o n t a i n i n g Na , +  and  secondly  production H  t h a t 16DM  C l " and  16DM HC0^~  does not break the g a s t r i c mucosal b a r r i e r .  of an i n c r e a s e d amount o f f l u i d by the pouches i n the absence o f  i n d i c a t e s t h a t t h i s cannot be the r e s u l t of back d i f f u s i o n and  +  and t h e r e f o r e must came from some o t h e r source. contains bicarbonate s e c r e t i o n and  The  damage,  f a c t t h a t the  suggests t h a t i t i s the r e s u l t o f n o n p a r i e t a l  confirms  t h e r e appears t o be 16DM  The  what was  suspected  cell  from the r a t s t u d i e s , a l t h o u g h  some s p e c i e s v a r i a t i o n .  does n o t break the b a r r i e r and  fluid  The  L i  +  data confirms  i n f a c t suggests t h a t i t may  that  tighten  it.  I t has E  been demonstrated t h a t d e s p i t e t h e i r a c i d i n h i b i t o r y a c t i o n the  prostaglandins  can  s t i m u l a t e c e r t a i n g a s t r i c mucosal c e l l s l e a d i n g t o  70  the p r o d u c t i o n  of mucus and n o n p a r i e t a l c e l l s e c r e t i o n .  It i s possible  t h a t t h e s e e f f e c t s c o n t r i b u t e s i g n i f i c a n t l y t o the p r o t e c t i v e a c t i o n o f prostaglandins.  A l t h o u g h the amount of HCO^  s e c r e t i o n i s s m a l l and  enough t o cause s i g n i f i c a n t n e u t r a l i z a t i o n of a c i d , the e x a c t mucus remains u n c e r t a i n .  The  p r o t e c t i v e p r o p e r t i e s o f the  demonstrated by Robert were f o r s t r o n g e r i n c r e a s e d mucus p r o d u c t i o n  The  would be  have o t h e r inhibition.  not  r o l e of  the  prostaglandins  l o c a l i r r i t a n t s , a s i t u a t i o n where  beneficial.  o t h e r importance of these two  t h a t these agents, and  the  s t u d i e s l i e s i n the  i n p a r t i c u l a r 16DM,  while  demonstration  inhibiting acid secretion  s e c r e t o r y e f f e c t s which have been masked by the p o t e n c y o f a c i d While t h e s e e f f e c t s may  even p h a r m a c o l o g i c a l l y , o f the e f f e c t o f 16DM  not be  important p h y s i o l o g i c a l l y o r  f a i l u r e to recognize  them has  on the g a s t r i c mucosal b a r r i e r .  l e d to m i s i n t e r p r e t a t i o n A l t h o u g h 16DM  most p o t e n t p r o s t a g l a n d i n both as an i n h i b i t o r of a c i d s e c r e t i o n and p r o t e c t i v e agent, i t has been c o n s i d e r e d  dangerous f o r c l i n i c a l  i s the as  a  evaluation  because of i t s apparent damaging e f f e c t on the g a s t r i c mucosal b a r r i e r . the b a s i s o f these s t u d i e s t h i s view of 16DM and  i t may  soon become a v a i l a b l e f o r c l i n i c a l  In the t h i r d study the a b i l i t y of PGE b a r r i e r damage was 16DM  was  Na  +  s t u d i e d and  2  and  15M  to reverse  +  established  compared w i t h the e f f e c t of metiamide. p l a n n e d 16DM  was  a b a r r i e r breaker.  r e s u l t s have been c a l c u l a t e d as NIF  and H .  unwarranted  evaluation.  not s t u d i e d because a t the time t h i s study was  considered  The  would appear t o be  The  c a l c u l a t i o n of  On  and p e r m e a b i l i t y  factors for  (K) from the computer c a l c u l a t e d s l o p e  of  71  the  r e g r e s s i o n l i n e f o r the l o g o f the c o n c e n t r a t i o n o f the i o n s i s more  a c c u r a t e than the n e t i o n f l u x c a l c u l a t e d from the f i r s t and l a s t as i t i n v o l v e s the use o f a l i n e based on seven p o i n t s . s i g n i f i c a n t d i f f e r e n c e between the volumes in  values,  As t h e r e i s no  o f f l u i d produced by the pouches  the f i v e treatment groups and the groups w i t h which they a r e compared,  (Table XVI) and a c t i v e s e c r e t i o n does n o t o c c u r w i t h the agents used, method o f c a l c u l a t i o n i s c o n s i d e r e d v a l i d . the  this  The c o n c l u s i o n s a r e based on  (K) r e s u l t s - t h e NIF d a t a i s used f o r s u p p o r t .  A f t e r d e m o n s t r a t i n g the v a l i d i t y o f the model i t was n e c e s s a r y t o compare the degree o f damage i n the Damage P e r i o d i n a l l the groups as t h i s can be used as an i n d i c a t i o n o f the degree o f damage p r e s e n t i n the Recovery P e r i o d t o which the v a r i o u s t h e r a p e u t i c agents are a p p l i e d . in  and  the Damage P e r i o d p r i o r t o treatment w i t h t o p i c a l 15M were s i g n i f i c a n t l y  lower than i n the u n t r e a t e d group i n d i c a t i n g t h a t the degree o f damage produced was l e s s .  I n the o t h e r f o u r treatment groups the degree o f damage  was comparable w i t h the u n t r e a t e d groups.  T o p i c a l PGE„ had no e f f e c t on K + and K + i n d i c a t i n g no e f f e c t on the 2 H Na damaged b a r r i e r . the  T o p i c a l 15M caused a s i g n i f i c a n t r e d u c t i o n i n  degree o f damage was i n s u f f i c i e n t no c o n c l u s i o n can be drawn.  + b u t as It i s  l i k e l y t h a t t h i s agent had no e f f e c t when a p p l i e d t o p i c a l l y , b u t f u r t h e r t e s t s i n which comparable  degrees o f damage were f i r s t produced would be  necessary t o e s t a b l i s h t h i s c o n c l u s i v e l y .  Given i n t r a v e n o u s l y , b o t h P G E  2  and 15M caused a s i g n i f i c a n t r e d u c t i o n i n K + and K + i n d i c a t i n g t h a t i n the ^ Na H * presence o f e x i s t i n g g a s t r i c mucosal damage these agents had a b e n e f i c i a l effect.  The p e r m e a b i l i t y f a c t o r s measured d u r i n g the r e c o v e r y p e r i o d on  VOLUMES PRODUCED (ml/1 hour) EXPERIMENT  DAMAGE PERIOD  RECOVERY PERIOD  CONTROL  13.28  + 0.96  13.18  + 1.62  ASA  13.63  + 1.28  13.37  + 1.83  15.22  + 0.86  17.72  + 1.77  16.85  + 1.46  18.40  + 2.92  14.30  + 0.89  11.20  + 0.67  TOP. P G E  2  TOP. 15M I.V.  PGE  I.V.  15M  16.45  + 1.23  13.10  + 0.94  I.V.  METIAMIDE  12.99  + 0.85  13.94  + 1.65  2  TABLE XVI:  Volumes produced by the pouches i n the v a r i o u s e x p e r i m e n t a l groups (Mean ± S.E.)  73  treatment w i t h  the two agents were the same as i n the o r i g i n a l c o n t r o l  experiments when the pouches were n o t exposed t o a s p i r i n .  Therefore  i n the  presence o f e x i s t i n g g a s t r i c mucosal b a r r i e r damage these agents were a b l e t o r e s t o r e g a s t r i c mucosal p e r m e a b i l i t y t o normal l e v e l s .  This e f f e c t  was  not produced by metiamide.  The  f a i l u r e o f metiamide t o i n f l u e n c e g a s t r i c mucosal p e r m e a b i l i t y  these c i r c u m s t a n c e s i n d i c a t e s t h a t t h i s e f f e c t o f the p r o s t a g l a n d i n s ,  under  which  c o u l d be r e g a r d e d as t h e r a p e u t i c r a t h e r than simply p r o t e c t i v e i s independent of a c i d i n h i b i t i o n . used was c o n f i r m e d  The a c i d i n h i b i t o r y p o t e n t i a l o f t h e b a t c h  o f metiamide  (Appendix 1 ) .  A r e d u c t i o n i n mucosal b l o o d  flow c o u l d reduce i o n i c f l u x e s and account 64 65  f o r t h e f i n d i n g s i n the Recovery P e r i o d . show t h a t the r e d u c t i o n i n mucosal b l o o d  However s t u d i e s i n the dog flow a s s o c i a t e d w i t h  '  the i n h i b i t i o n  o f s t i m u l a t e d a c i d s e c r e t i o n by PGE^ i s the r e s u l t and n o t the cause o f a c i d i n h i b i t i o n , and s t u d i e s i n r a t s has  6 6  i n d i c a t e t h a t under b a s a l c o n d i t i o n s  a v a s o d i l a t o r e f f e c t on the g a s t r i c mucosa.  blood  PGE^  The e f f e c t o f 15M on b a s a l  flow has n o t been s t u d i e d . There i s e v i d e n c e t h a t a s p i r i n ^ and i n d o m e t h a c i n ^ can damage the 6  6  sodium pump l e a d i n g t o the accumulation o f i n t r a c e l l u l a r sodium and water. Such an e f f e c t c o u l d u l t i m a t e l y l e a d t o c e l l l y s i s .  16DM has t h e o p p o s i t e  e f f e c t s t i m u l a t i n g the sodium pump. ^ 6  I t i s p o s s i b l e t h a t an i n c r e a s e i n g a s t r i c mucosal p e r m e a b i l i t y r e s u l t s from the i n t e r f e r e n c e w i t h the normal homeostasis o f mucosal c e l l s and t h a t  74  i n these experiments biochemical but not s t r u c t u r a l damage was induced by a s p i r i n and then reversed by the infusion of PGE and 15M assuming these 2  agents have the same c e l l u l a r e f f e c t s as 16DM.  The rapid restoration of  c e l l u l a r homeostasis would return the mucosal epithelium to normal and lead to a return to normal permeability.  I f this explanation i s correct one  would expect 16DM to have the same e f f e c t .  Now that the confusion over the  permeability e f f e c t of 16DM has been c l a r i f i e d this could be studied.  Such a mechanism would explain why the protective action of the prosta glandins i s unrelated to acid secretory i n h i b i t i o n .  The evidence provided  here of the reversal of b a r r i e r damage i n addition to the known acid i n h i b i t o r y action of the prostaglandins could make them i d e a l therapeutic agents i n acute g a s t r i c mucosal lesions. reports of the value of the  I t i s i n t e r e s t i n g to note that despite early . . 69 receptor antagonists i n erosive g a s t r i t i s ,  their value i n stress induced upper g a s t r o i n t e s t i n a l t r a c t haemorrhage has 70  recently been  questioned.  75  CONCLUSIONS  The  conclusions  three  t h a t can be drawn from the f i r s t experiment are t h a t  prostaglandins  a p p l i e d t o p i c a l l y t o the r a t stomach s t i m u l a t e a  p a r i e t a l c e l l s e c r e t i o n and  16DM  and PGE  2  s t i m u l a t e mucus p r o d u c t i o n  t o an i n c r e a s e i n the f r e e component of mucus, but have no e f f e c t on barrier fraction.  Given i n t r a v e n o u s l y a l l t h r e e  The E  2  not s t i m u l a t e d by i n t r a v e n o u s  t o p i c a l l y and contained  2  Nonparietal  final and  In the dogs 16DM  i n t r a v e n o u s l y caused an i n c r e a s e i n the  sodium, c h l o r i d e and b i c a r b o n a t e .  P  s e c r e t i o n i n the  G  E  a n c 2  *  fluid  cell  can r e v e r s e  the  both  s e c r e t e d which  d i d not  stimulate  dog.  experiment demonstrates t h a t the i n t r a v e n o u s  15M  This property and  the  administration.  on n o n p a r i e t a l c e l l s e c r e t i o n .  nonparietal c e l l bicarbonate  of PGE  leading  second experiment i n d i c a t e d a s p e c i e s v a r i a t i o n i n the e f f e c t o f  prostaglandins  The  non  agents cause an i n c r e a s e i n  f r e e mucus but w i t h o u t an i n c r e a s e on the b a r r i e r f r a c t i o n . s e c r e t i o n was  the  administration  e s t a b l i s h e d g a s t r i c mucosal b a r r i e r damage.  i s not e x h i b i t e d by t o p i c a l a p p l i c a t i o n of the  i t i s not p o s s e s s e d by metiamide.  prostaglandins,  76  RATS  VOLUME in ml.  ACID OUTPUT yeq H /3 Hr  ALCIAN BLUE BOUND (in mg.) MUCOSA  CONTENTS  TOTAL  1  4.1  107  0.70  0.32  1.02  2  4.0  68  0.81  0.94  1.75  3  3.8  76  0.92  0.89  1.81  4  4.0  68  0.70  0.83  1.53  5  4.3  60  0.92  0.78  1.70  6  4.0  24  1.17  0.48  1.65  7  4.1  131  0.88  0.37  1.25  8  4.0  88  0.44  0.71  1.15  9  4.1  41  0.88  0.12  1.00  10  4.1  41  0.59  0.24  0.83  4.05 ±0.03  70.4 ±10.2  0.80 ±0.06  0.57 ±0.09  1.37 ±0.11  MEAN ± S.E.  TABLE XVII:  Experiment 1:  Topical prostaglandins:  Controls  77  RATS  VOLUME i n ml.  ALCIAN BLUE BOUND ( i n mg.) ACID OUTPUT yeq H /3 Hr  MUCOSA  CONTENTS  TOTAL  1  6.4  45.0  0.16  1.16  1.32  2  6.2  6.2  0.16  1.29  1.45  3  4.2  0  0.22  1.09  1.31  4  6.2  18.6  0.38  1.13  1.51  5  6.6  52.8  0.54  1.72  2.26  6  5.3  42.0  0.88  2.99  3.87  7  4.8  19.0  0.88  1.14  2.02  8  4.5  27.0  0.44  1.87  2.31  9  5.1  20.0  0.51  1.06  1.57  10  5.2  0.37  0.93  1.30  0.45 ±0.08  1.44 ±0.19  1.89 ±0.25  0  MEAN ± S.E.  5.45 ±0.27  TABLE XVIII:  Experiment 1:  23.1 ±5.9  Topical prostaglandins:  15M 10 yg/ml  78  ALCIAN BLUE BOUND ( i n mg.) RATS  VOLUME i n ml.  ACID OUTPUT yeq H /3 Hr  MUCOSA  CONTENTS  TOTAL  1  5.4  5.4  1.35  0.14  1.49  2  5.2  16.0  0.49  1.79  2.28  3  5.0  8.0  0.81  1.95  2.76  4  5.4  38.0  1.25  3.36  4.61  5  5.3  16.0  1.03  2.75  3.78  6  5.0  20.0  0.37  1.19  1.56  7  4.8  24.0  0.37  1.14  1.51  8  5.1  20.0  0.37  1.66  2.03  9  4.8  34.0  0.44  0.57  1.01  10  4.6  23.0  0.22  2.05  2.67  0.67 ±0.13  1.66 ±0.30  2.33 ±0.35  MEAN ± S.E.  TABLE XIX:  5.07 ±0.08  Experiment 1:  20.44 ±3.22  Topical Prostaglandins:  16DM 10 yg/ml.  79  ALCIAN BLUE BOUND ( i n mg.) VOLUME i n ml.  ACID OUTPUT yeq H /3 Hr  MUCOSA  CONTENTS  TOTAL  1  7.9  40.0  0.88  1.54  2.42  2  6.9  41.0  0.32  0.16  0.48  3  8.3  0  0.16  4.74  4.90  4  8.3  0  1.76  1.29  3.05  5  7.2  0  1.60  4.11  5.71  6  5.8  11.6  0.44  3.10  3.54  7  5.2  0  0.22  2.05  2.27  8  6.7  0  0.66  1.59  2.25  RATS  9 10 MEAN ± S.E.  TABLE XX:  DIED DURING THE COURSE OF EXPERIMENT 5.0 6.82 ±0.41  Experiment 1:  22.0 12.7 ±5.82  0.44  0.89  1.33  0.72 ±0.19  2.16 ±0.51  2.88 ±0.55  Topical Prostaglandins:  PGE  100 yg/ml  80  ALCIAN BLUE BOUND ( i n mg.) RATS 1  VOLUME i n ml.  ACID OUTPUT yeq H /3 Hr  MUCOSA  CONTENTS  TOTAL  4.0  64.0  0.60  1.28  1.88  2  DIED DURING COURSE OF EXPERIMENT  3  3.5  35.0  0.70  1.93  2.63  4  4.0  32.0  0.85  1.92  2.77  5  4.0  32.0  0.70  1.28  1.98  3.88 ±0.12  40.75 ±7.78  0.71 ±0.04  1.60 ±0.18  2.31 ±0.22  MEAN ± S.E.  TABLE XXI:  Experiment 1:  Intravenous P r o s t a g l a n d i n s :  Controls  81  ALCIAN BLUE BOUND ( i n mg.) RATS  VOLUME i n ml.  ACID OUTPUT yeq H /3 Hr  MUCOSA  CONTENTS  TOTAL  1  4.4  70.4  1.05  4.62  5.67  2  4.3  112.0  1.00  4.82  5.82  3  INTRAVENOUS CANNULA DISLODGED  4  4.3  95.0  0.90  4.97  5.87  5  4.2  52.0  0.95  4.95  5.90  4.22 +0.02  82.4 ±13.24  MEAN ± S.E.  TABLE XXII:  0.98 ±0.03  Experiment 1: Intravenous 15M 0.6 yg/Kg/Hr.  4.72 ±0.11  Prostaglandins:  5.82 +0.04  82  ALCIAN BLUE BOUND ( i n mg.) VOLUME i n ml.  ACID OUTPUT yeq H /3 Hr  MUCOSA  CONTENTS  TOTAL  1  4.1  16.4  0.57  1.48  2.05  2  4.0  56.0  0.70  3.83  4.53  3  4.1  45.1  0.44  2.06  2.50  4  4.0  60.0  0.60  3.74  4.34  5  4.0  48.0  0.72  2.97  3.69  MEAN ± S.E.  4.04 ±0.02  45.1 ±7.7  0.61 ±0.05  2.82 ±0.46  3.42 ±0.49  TABLE X X I I I :  Experiment 1: Intravenous P r o s t a g l a n d i n s : 16DM 0.6 yg/Kg/Hr.  RATS  83  ALCIAN BLUE BOUND ( i n mg.) RATS  VOLUME i n ml.  ACID OUTPUT yeq 1^/3 Hr  MUCOSA  CONTENTS  TOTAL  1  4.3  30.1  1.20  3.20  4.40  2  4.4  35.2  1.33  5.20  6.53  3  4.3  43.0  0.76  2.40  3.16  4  4.4  35.2  0.85  3.77  4.62  5  4.1  36.9  0.70  4.12  4.82  MEAN ± S.E.  4.3 ±0.05  36.1 ±2.07  0.97 ±0.12  3.74 ±0.47  4.70 ±0.54  TABLE XXIV:  Experiment 1: Intravenous P r o s t a g l a n d i n s : PGE 0.6 mg/Kg/Hr.  84  ALCIAN BLUE BOUND ( i n mg.) VOLUME i n ml.  ACID OUTPUT yeq H /3 Hr  MUCOSA  CONTENTS  TOTAL  1  4.1  164.1  0.60  0.37  0.97  2  4.0  96.0  0.15  0.32  0.47  3  4.1  176.3  0.40  0.39  0.79  4  4.3  90.3  0.60  0.60  1.20  5  4.2  210.0  0.80  0.59  1.39  4.14 ±0.01  147.34 ±23.38  0.51 ±0.11  0.45 ±0.06  0.96 ±0.16  RATS  MEAN ± S.E.  TABLE XXV:  Experiment 1:  Subcutaneous H i s t a m i n e :  Controls.  85  ALCIAN BLUE BOUND ( i n mg.) RATS  VOLUME i n ml.  ACID OUTPUT yeq H /3 Hr  MUCOSA  CONTENTS  TOTAL  6  5.2  343.2  0.30  0.40  0.70  7  4.3  116.1  0.40  0.69  1.09  8  4.3  64.5  0.20  0.56  0.76  9  4.2  134.4  0.20  0.42  0.62  10  6.0  576.0  0.20  0.36  0.56  0.26 ±0.04  0.49 ±0.06  0.75 ±0.09  MEAN ± S.E.  TABLE XXVI:  4.80 ±0.34  246.84 ±95.03  Experiment 1: Subcutaneous H i s t a m i n e : H i s t a m i n e 6 mg/Kg/Hr.  86  BICARBONATE SECRETED yeq/3 Hr EXPERIMENT  DOG 3  DOG 13  DOG 16  DOG 23  CONTROL  183.73  0 0 212.4  161.73 70.73 119.28  227.84  121.99 ± 31.96  15M 10 ug/ml  224.0 222.75  167.25 254.05  247.73 305.36  111.64 316.47  231.15 ± 23.93  16DM 10 yg/ml  960.57 821.25  115.80 332.65  735.50 330.98  396.45 173.78  483.37 ± 110.99  PGE  178.59 0  0 65.07  55.89 29.71  118.32 0  2  100 yg/ml  TABLE XXVII:  MEAN ± S.E.  55.95 ±  Experiment 2: T o p i c a l P r o s t a g l a n d i n : B i c a r b o n a t e S e c r e t i o n yeq/3 Hr.  22.79  VOLUME PRODUCE ( i n ml/3 Hr) EXPERIMENT  DOG 3  DOG 13  DOG 16  DOG 23  CONTROL  38.09  20.56 13.84 6.98  18.41 11.65 14.32  21.46  18.16 ± 3.31  15M 10 yg/ml  20.50 14.00  20.25 10.69  19.55 20.02  20.32 22.04  18.42 ± 1.39  16DM 10 yg/ml  38.39 55.75  22.40 31.03  38.05 38.05  43.79 34.01  37.68 ± 3.42  PGE  23.04 24.03  7.88 20.17  23.91 20.39  35.31 23.69  22.30 ± 2.65  2  100 yg/ml  TABLE XXVIII:  MEAN ± S.E.  Experiment 2: T o p i c a l P r o s t a g l a n d i n s : Volume S e c r e t e d ml/3 Hr.  88  .+  Cl DOG  NIF  Li  Na  K  NIF  K  +  NIF  +  K K  NIF  K  1.70 -0.16 0.59  30.56 18.45 29.48  11.37 13.05 19.79  13  157.48 -96.61 49.53  0.98 -0.61 0.31  0.21 -5.49 -4.60  0.02 -1.30 -1.05  262.68 -25.15 83.58  16  55.22 149.52 9.59  0.34 0.98 0.07  -5.53 -3.35 -4.89  -1.53 -9.83 -1.22  57.34 176.74 9.42  0.38 1.14 0.007  17.24 33.50 20.50  10.11 20.19 8.13  23  203.09  1.31  -0.73  -0.19  262.14  1.69  33.70  15.94  3  435.67  3.09  -1.40  -0.46  467.22  3.30  32.09  20.51  119.60 ±56.30  0.80 ±0.38  -3.22 ±0.80  -0.82 ±0.17  161.74 ±58.08  1.08 ±0.38  26.94 ±2.47  14.88 ±1.73  MEAN ± S.E.  TABLE XXIX:  Experiment 2: Controls.  Topical Prostaglandins:  P e r m e a b i l i t y Data:  89  Cl DOG  NIF  13  1.00 87.17  16  Li NIF  K  0.09 0.58  1.31 -2.03  0.35 -0.53  173.66 137.50  200.60 190.97  1.33 1.34  -1.41 -0.88  -0.37 -0.16  3  246.49 38.45  1.57 0.22  3.97 -2.44  23  101.16 138.22  0.67 1.02  MEAN ± S.E.  125.50 ±29.84  0.85 +0.17  TABLE XXX:  K  Na  Experiment 2: 15M 10 yg/ml  NIF  K  1.25 1.01  14.59 20.19  14.81 13.84  201.81 238.47  1.47 1.77  19.37 20.05  16.28 13.51  0.99 -0.64  384.85 154.27  2.73 1.10  16.52 12.25  18.09 13.53  -5.33 -4.94  -1.47 -1.40  263.48 284.32  1.79 2.12  35.41 30.36  19.45 17.43  -1.46 ±1.08  -0.40 ±0.28  229.79 ±28.77  1.65 ±0.20  21.09 ±2.79  15.80 ±0.80  Topical  NIF  K  Prostaglandin:  K  Permeability  Data:  90  Cl DOG  NIF  -  .+ Lx K  Na  NIF  K  +  NIF  K K  +  NIF  K  13  268.97 255.09  1.86 1.86  7.53 -1.57  1.86 -0.38  344.43 358.39  2.45 2.54  23.42 22.58  12.84 17.22  16  729.64 290.54  5.45 2.09  -6.63 -3.65  -3.03 -1.18  850.81 465.53  6.11 3.34  49.92 26.81  19.50 15.78  3  703.91 872.21  5.04 6.43  -4.05 -2.17  -1.85 -0.48  950.60 927.97  6.72 6.53  32.56 34.82  19.02 20.58  23  734.99 570.91  5.33 4.11  1.10 2.24  0.26 0.81  750.87 682.83  5.50 4.90  40.50 37.28  25.33 22.21  MEAN ± S.E.  553.28 ±87.38  4.02 ±0.64  -0.90 ±1.56  -0.49 ±0.53  666.42 ±87.57  4.76 ±0.61  33.48 ±3.27  19.06 ±1.36  TABLE XXXI:  Experiment 2: T o p i c a l P r o s t a g l a n d i n s : 16DM 10 pg/ml.  Permeability  Data:  91  +  Cl  Li  Na  +  DOG  NIF  K  NIF  K  13  238.91 -136.70  1.49 -0.86  -0.66 -6.48  -0.23 -1.54  263.25 -62.63  1.76 -0.43  16  184.78 367.55  1.18 2.39  -4.99 -1.09  -1.53 -0.20  208.86 366.41  3  22.07 647.92  0.18 3.91  -0.62 1.55  -0.16 0.35  23  230.81 336.50  1.61 2.13  -5.95 -6.94  MEAN ± S.E.  236.48 ±82.85  1.50 ±0.50  -3.14 ±1.15  TABLE XXXII:  NIF  +  K NIF  K  35.57 15.40  18.97 10.15  1.43 2.55  27.71 27.37  15.41 21.03  303.97 458.23  2.08 3.21  20.97 18.09  21.08 21.83  -1.77 -2.36  267.69 336.31  1.86 2.46  28.28 72.40  13.41 26.39  -0.93 ±0.34  267.76 ±54.22  1.86 ±0.37  30.72 ±6.37  18.53 ±1.84  Experiment 2: T o p i c a l P r o s t a g l a n d i n : PGE 100 yg/ml. 2  K  P e r m e a b i l i t y Data:  92  BICARBONATE SECRETION yeq/3 Hr EXPERIMENT  DOG 4  CONTROL  24.44 137.73  15M  0 0  DOG 12  DOG 16  92.14 88.26  115.46 69.29  75.10 47.35 580.59 418.11  DOG 23  MEAN ± S.E.  0 0  65.91 ± 18.52  44.99 52.41  0 22.12  30.13 ± 10.11  113.18 314.90  289.15 0  317.78 ± 66.27  0.6 yg/Kg/Hr 16DM 0.6 yg/Kg/Hr  462.84 363.48 45.23 47.44  0 0  86.14 48.05  272.1 0  62.37 ± 31.88  PGE 0.6 mg/Kg/Hr  TABLE XXXIII:  Experiment 2: Intravenous P r o s t a g l a n d i n : B i c a r b o n a t e S e c r e t i o n yeq/3 Hr.  93  VOLUME PRODUCE ( i n ml/3 Hr) EXPERIMENT  DOG 4  DOG 12  DOG 16  DOG 23  MEAN ± S.E.  CONTROL  13.37 10.41  11.20 8.63  22.23 10.69  8.47 22.50  13.43 ± 2.01  15M  8.87 11.59  13.90 11.85  9.49 16.91  14.16 8.94  11.91 ± 1.01  25.08 30.63  24.23 29.01  17.77 27.48  19.28 22.33  24.47 ± 1.60  11.94 9.77  12.25 14.34  7.57 12.55  18.92 9.48  12.10 ± 1.22  10 yg/ml 16DM 0.6 yg/Kg/Hr PGE 0.6 mg/Kg/Hr  TABLE XXXIV:  Experiment 2: Intravenous P r o s t a g l a n d i n : Volume s e c r e t e d ml/3 Hr.  94  +  Cl DOG  NIF  Li  Na  K  NIF  K  NIF  +  +  K K  NIF  K  16  -50.47 128.57  -0.36 0.96  -3.09 -3.21  -0.81 -0.81  -18.05 145.01  -0.13 1.15  14.06 24.10  10.59 14.57  23  71.17 128.53  0.49 0.92  -5.88 -2.41  -1.74 -0.66  103.63 167.47  0.73 1.22  20.39 11.81  21.16 12.92  4  -86.11 101.63  -0.60 0.71  -7.70 -3.01  -2.00 -0.78  -86.79 109.79  -0.61 0.79  15.02 22.74  14.58 16.87  12  -108.39 69.00  -0.77 0.49  -10.81 -5.94  -2.96 -1.43  -107.74 30.01  -0.79 0.23  13.70 15.50  11.00 16.43  31.74 ±34.55  0.23 ±0.25  -5.25 ±0.28  -1.39 ±37.20  42.91 ±37.20  0.32 ±0.26  17.16 ±1.61  14.76 ±1.21  MEAN ± S.E.  TABLE XXXV:  Experiment 2: Controls.  Intravenous P r o s t a g l a n d i n s :  P e r m e a b i l i t y Data:  95  Li  Cl DOG  NIF  N  +  K  NIF  K  NIF  K  NIF  K  4  -42.11 -7.57  -0.30 -0.06  -3.46 -4.38  -0.88 -1.19  -58.37 -75.33  -0.42 -0.55  11.71 12.15  14.67 14.81  23  -67.78 -4.52  -0.46 -0.05  -9.04 -5.75  -2.45 -1.69  -63.29 20.20  -0.44 0.12  28.16 15.66  19.96 5.95  16  71.01 -114.45  0.52 -0.81  -3.40 -7.71  -0.92 -2.00  49.99 -105.21  0.37 -0.75  27.70 32.36  15.11 25.20  12  -41.20 -47.68  -0.30 -0.34  -3.04 -2.04  -0.83 -0.51  -40.02 -50.84  -0.30 -0.36  4.36 6.67  5.42 6.82  MEAN ± S.E.  -31.78 ±19.12  -0.22 ±0.10  -4.85 ±0.86  -1.30 ±0.22  -40.35 ±18.03  -0.29 ±0.10  17.34 ±3.76  13.11 ±2.38  TABLE XXXVI:  Experiment 2: Intravenous P r o s t a g l a n d i n s : 15M 0.6 yg/Kg/Hr.  P e r m e a b i l i t y Data:  96  -  +  Cl DOG  NIF  +  Li K  +  Na  NIF  K  NIF  K K  NIF  K 16.98 20.14  12  433.92 515.99  3.06 3.61  -4.85 -2.22  -1.46 -0.57  519.54 644.89  3.75 4.34  19.67 23.46  23  271.77 217.28  1.94 1.52  -2.85 -3.96  -0.83 -1.12  330.32 257.10  2.35 1.83  27.19 20.78  4  481.15 394.88  3.42 2.74  -0.76 -2.17  -0.35 -0.64  567.71 531.32  4.12 3.71  22.93 24.69  17.22 18.49  16  213.79 376.97  1.49 2.64  -4.55 1.52  -1.11 0.22  74.03 449.92  0.73 3.34  24.52 36.61  10.95 22.00  MEAN ± S.E.  363.21 ±41.28  2.55 ±0.28  -2.48 ±0.74  -0.73 ±0.17  421.85 ±66.79  3.02 ±0.43  24.98 ±1.85  17.27 ±1.70  TABLE XXXVII:  Experiemnt 2: Intravenous P r o s t a g l a n d i n s : 16DM 0.6 yg/Kg/Hr.  22.85 9.56  P e r m e a b i l i t y Data:  97  Cl DOG  +  Li' K  NIF  K  NIF  K  NIF  K  -12.75 -44.81  -0.10 -0.31  -4.77 -6.22  -1.24 -1.66  -8.98 -52.79  -0.06 -0.39  21.76 21.71  19.69 17.32  12  68.90 70.68  0.47 0.51  -4.66 -3.62  -1.16 -0.90  40.98 11.10  0.30 0.10  22.14 21.37  18.09 17.50  23  176.29 -54.44  1.27 -0.37  -4.62 -9.68  -1.20 -2.44  212.77 0.76  1.52 0.10  31.07 19.48  17.44 16.63  16  5.17 109.27  0.03 0.76  -1.34 -2.44  -0.32 -0.66  23.66 18.41  0.17 0.14  13.65 11.56  10.96 12.71  MEAN ±.S.E.  39.66 ±28.46  0.28 ±0.20  -4.66 ±0.88  -1.19 ±0.22  0.22 ±0.17  20.34 ±2.09  16.29 ±1.03  4  NIF  Na  TABLE XXXVIII:  30.73 ±27.80  Experiment 2: I n t r a v e n o u s P r o s t a g l a n d i n s : PGE 0.6 yg/Kg/Hr. 2  P e r m e a b i l i t y Data:  98  RECOVERY PERIOD  DAMAGE PERIOD NIF ueq/min  K  NIF ueq/min  K Volume ml/Hr  H  Na  H  Volume ml/Hr  13.38 3.28  -1.51 -5.24  0.30 0.08  -0.11 -0.06  17.45 8.03  15.81  11.77  0.23  11.58 9.21  -2.47 -5.50  0.27 0.22  -0.11 -0.10  9.60 9.23  10.74  2.40  0.23  -0.07  10.64  16.11 13.69  -7.89 -8.23  0.37 0.32  -0.16 -0.14  11.85 11.26  13.19  7.18  0.22  -0.10  14.83  6.29 10.65  2.45 6.78  0.14 0.19  -0.05 -0.09  11.87 15.15  6.24  -5.84  0.18  -0.08  7.53  25.04 10.60  -9.08 -3.90  0.54 0.23  -0.23 -0.13  13.06 11.07  16.49  1.88  0.35  -0.02  12.58  22.87 19.01  -7.75 3.42  0.48 0.31  -0.21 -0.15  12.72 15.09  23.39  -4.31  0.46  -0.02  13.39  25.67 27.20  -5.91 16.04  0.51 0.41  -0.22 -0.19  16.81 27.20  25.71  5.3  0.38  -0.23  23.42  14.29 17.23  -2.52 2.13  0.33 0.37  -0.13 -0.15  11.92 14.04  14.81  -4.59  0.25  -0.15  9.92  12.71 9.52  -3.79 -13.12  0.24 0.26  -0.17 -0.16  17.74 8.87  5.25  -16.48  0.19  -0.14  8.36  8.41 11.16  -2.95 -0.79  0.20 0.25  -0.07 -0.09  9.10 13.7 2  11.12  -3.00  0.27  -0.11  10.79  14.39 ±1.47  -2.49 ±1.44  0.30 ±0.03  -0.13 ±0.01  13.28 ±0.96  14.27 ±2.08  -0.56 ±2.53  0.27 ±0.03  -0.12 ±0.02  13.18 ±1.62  Na  XXXIX:  Experiment 3:  Na  +  H  +  + Na  + H -0.12  P e r m e a b i l i t y Data And Volumes F o r Each P e r i o d :  20.40  Controls.  99  DAMAGE PERIOD NIF yeq/min  DOG 14  15  21  22  17  MEAN ± S.E.  RECOVERY PERIOD  K  NIF yeq/min  K  H  Na  H  Volume ml/Hr  12.49 12.16  -8.70 -9.00  0.29 0.30  -0.17 -0.16  ^'ft 8 .68  13.51  -7.63  0.35  -0.13  8.94  14.58 11.19  2.75 -4.29  0.20 0.20  -0.17 -0.14  19.87 15.17  14.88  0.21  0.26  -0.13  12.88  14.81 12.80  -0.78 -9.99  0.32 0.31  -0.17 -0.16  17.58 8.03  15.40  -12.59  0.40  -0.17  10.76  11.78 13.90  -15.35 -14.30  0.31 0.37  -0.17 -0.18  12.13 13.38  10.41  -5.07  0.26  -0.12  10.76  28.67 35.02  -28.37 -16.90  0.57 0.60  -0.41 -0.43  14.62 25.86  29.96  -30.35  0.65  -0.36  13.66  37.13 49.39  -27.74 -37.82  0.64 0.71  -0.49 -0.61  9.10 18.73  43.81  -21.36  0.64  -0.46  19.73  27.89 20.45  -16.22 -21.16  0.55 0.50  -0.39 -0.26  21.69 9.73  23.17  10.66  0.43  -0.19  26.81  28.97 34.46  -33.07 -34.50  0.52 0.59  -0.44 -0.50  12.29 10.38  25.10  -8.14  0.41  -0.24  12.70  25.60 12.14  -4.79 -12.77  0.42 0.29  -0.31 -0.20  19.85 10.15  12.94  -9.62  0.34  -0.13  7.37  32.92 13.68  -18.41 -20.42  0.27 0.36  -0.19 -0.20  12.57 10.97  13.88  -8.19  0.36  -0.13  10.08  22.50 ±2.50  -16.64 ±2.54  0.42 ±0.03  -0.29 ±0.04  13.63 ±1.28  20.30 ±3.28  -9.20 0.41 ±3.51 ±0.05  -0.21 ±0.04  13.37 ±1.83  Na  TABLE XL:  Experiment 3:  Na  H  Na  Volume ml/Hr  H  P e r m e a b i l i t y Data And Volumes f o r Each P e r i o d :  A s p i r i n Damage.  100  RECOVERY PERIOD  DAMAGE PERIOD NIF yeq/min  NIF yeq/min  K  H  Na  H  Volume ml/Hr  7.76  1.62  0.08  -0.14  14.55  31.97 20.52  -1.23 -7.84  0.60 0.47  -0.30 -0.21  13.40 18.25  -4.60 -8.36  0.20 0.27  18.10 14.26  -6.40 -17.55  36.51  K Volume ml/Hr  +  + Na  H  13.68  5.49  0.26  -0.10  17.31  21.43 12.59  25.91  3.01  0.43  -0.18  18.01  -0.17 -0.20  13.60 17.69  9.22  -1.81  0.12  -0.06  8.26  0.35 0.33  -0.23 -0.25  18.43 8.71  29.26  -4.08  0.48  -0.22  20.86  -26.57  0.77  -0.44  17.11  37.32  0.45  0.61  -0.29  23.08  13.92 21.89  -16.34 -6.22  0.27 0.31  -0.21 -0.23  12.93 20.51  1.88  -11.52  -0.01  -0.15  10.54  22  3.74 14.24  -8.54 -27.62  0.05 0.41  -0.24 -0.29  16.16 8.96  25.18  -10.79  0.44  -0.29  15.09  17  23.09 16.73  -14.32 -6.57  0.25 0.26  -0.29 -0.18  19.37 13.86  32.63  0.13  0.25  -0.29  27.62  26.35 23.92  -11.12 -11.16  0.34 0.35  -0.32 -0.25  17.29 16.32  28.38  -5.45  0.31  20.77 21.66  -15.65 -15.94  0.43 0.44  -0.31 -0.3 0  12.29 12.34  34.62  -0.62  -0.25 ±0.01  15.22 ±0.86  23.80 ±3.69  -3.41 0.34 ±1.86 ±0.06  DOG  Na  14 15  21  MEAN ± S.E.  19.28 ±1.85  TABLE X L I :  -11.35 0.35 ±1.83 ±0.04  Na  H  P e r m e a b i l i t y Data And Volumes f o r Each P e r i o d :  0.47  T o p i c a l PGE  -0.26  -0.35 -0.22 ±0.30  18.23  18.24 17.74 ±1.77  10 yg/ml.  101  RECOVERY PERIOD  DAMAGE PERIOD NIF ueq/min  K  NIF ueq/min Na+  H  Na  H  Volume ml/Hr  13.86 6.89  -8.98 -9.12  0.21 0.13  -0.17 -0.11  13.72 13.94  17.82  11.21 8.59  0.64 -13.63  0.12 0.19  -0.15 -0.14  13.92 9.90  37.36 10.92  -10.24 -20.68  0.53 0.23  -0.37 -0.19  34.15 23.26  -3.40 -11.63  0.39 0.34  21  16.05 7.85  9.88 -2.19  17  29.65 11.28  DOG 14  15  MEAN ± S.E.  K  Na  H  6.44  0.22  -0.13  18.84  9.27  3.11  0.11  -0.08  12.05  23.56 12.72  24.82  -12.80  0.36  -0.27  17.63  -0.36 -0.26  30.29 24.34  18.11  -11.71  0.24  -0.24  18.99  0.08 0.09  -0.15 -0.11  18.24 12.90  15.12  -2.97  0.18  -0.17  17.37  -13.56 -4.57  0.45 0.17  -0.34 -0.12  21.18 20.57  33.63  16.58  0.29  -0.25  37.54  4.87 19.04  -5.29 0.51  0.04 0.26  -0.13 -0.18  9.82 14.98  14.47  3.77  0.22  -0.09  12.79  24.52 13.84  -15.94 -6.59  0.34 0.24  -0.36 -0.13  18.66 10.80  7.82  -5.59  0.13  -0.09  11.96  17.08 ±2.49  -7.14 ±1.86  0.24 ±0.03  -0.21 ±0.02  16.85 ±1.46  17.63 ±2.95  -0.39 ±3.48  0.22 ±0.03  -0.17 ±0.03  18.40 ±2.93  TABLE X L I I :  Na  H  Experiment 3: P e r m e a b i l i t y Data And Volumes F o r Each P e r i o d : T o p i c a l 15M 10 yg/ml.  102  RECOVERY PERIOD  DAMAGE PERIOD NIF  DOG 14  15  21  22  MEAN  ueq/min  NIF  K  H  Na  H  Volume ml/Hr  16.85 13.63  13.87 0.74  0.22 0.22  -0.13 -0.16  18.41 15.36  0.82  13.63 11.12  -0.60 3.14  0.34 0.19  -0.09 -0.15  11.16 14.48  0.70  11.84 9.79  4.16 -13.81  0.22 0.27  -0.11 -0.16  13.61 7.33  7.99  17.08 11.26  -12.22 -1.77  0.45 0.22  -0.19 -0.12  9.22 9.36  18.14 19.51  -2.04 -3.50  0.34 0.37  -0.22 -0.20  18.67 13.93  -8.48 -10.78  0.45 0.35  34.52 34.18  -34.63 -17.80  26.20 31.48  yeq/min  +  K  Na  H  ml/Hr  6.71  0.06  -0.03  11.35  4.00  -0.05  -0.04  8.77  1.24  0.18  -0.06  10.52  13.00  2.92  0.26  -0.10  11.02  24.95 14.92  7.57  -4.33  0.22  -0.05  10.27  -0.19 -0.17  14.23 9.21  8.82  3.29  0.21  -0.04  10.94  0.64 0.60  -0.53 -0.40  17.81 24.24  16.52  -10.60  0.37  -0.16  9.13  -19.20 -25.17  0.57 0.69  -0.35 -0.41  14.08 16.69  15.50  -2.68  0.35  -0.14  16.47  31.23 24.60  -35.03 -14.31  0.64 0.46  -0.48 -0.29  12.11 14.15  12.90  1.67  0.25  -0.09  11.29  25.17 26.31  -26.13 -18.70  0.61 0.50  -0.38 -0.34  10.81 17.70  14.48  -13.82  0.38  -0.18  14.94  26.67 33.28  -34.33 -22.23  0.53 0.63  -0.50 -0.39  16.92 14.31  12.22  -9.23  0.30  -0.13  8.60  18.47 21.28  -16.42 -27.48  0.40 0.55  -0.31 -0.35  12.38 9.87  15.89  -5.00  0.36  -0.19  11.20  21.20 ±1.62  -13.44 ±2.72  0.43 ±0.01  -0.27 ±0.03  14.30 ±0.89  10.52 -2.14 ±1.58 ±1.88  0.23 ±0.04  -0.10 ±0.01  11.20 ±0.67  Na  TABLE X L I I I :  Na  H  Experiment 3: P e r m e a b i l i t y Data and Volumes F o r Each P e r i o d : I.V. P G E 0.3 mg/Kg/Hr. 2  103  RECOVERY PERIOD  DAMAGE PERIOD NIF  ueq/min  H  Volume ml/Hr  0.11 0.06  -0.08 -0.08  5.45 11.58  10.99 2.85  0.18 0.13  -0.11 -0.14  18.72 15.78  18.07 9.28  11.55 -10.58  0.26 0.25  -0.14 -0.12  21.27 10.36  22.57 15.50  -10.05 13.10  0.33 0.17  -0.25 -0.07  16.72 19.85  -1.55 2.24  0.37 0.40  19.67 14.74  -23.44 0.21  H  DOG  Na  14  3.96 5.82  -10.23 -0.27  13.46 12.71  15  21  NIF  K  + Na  Na  K  ueq/min  +  H  +  +  Na  9.49 11.78  8.98  -0.03  14.25  -0.03  12.31  0.08  8.84  0.16  10.77  -0.35  0.24  -0.10  12.21  19.29 18.01  10.46  2.96  0.21  -0.05  13.59  -0.18 -0.18  17.04 16.97  9.09  -13.73  0.31  -0.10  0.36 0.17  -0.31 -0.14  8.05 13.38  0.26  -0.24  13.17  12.92 -0.06  -0.01  13.94  0.48  -0.23  14.64  18.24  -9.82  32.32 29.00  -1.74 24.87  0.58 0.25  -0.25 -0.14  20.81 26.27  2.47  39.13 31.25  -13.03 -21.54  0.65 0.60  -0.45 -0.39  23.31 16.28  18.73  22  26.92 37.11  -32.24 -24.63  0.64 0.74  -0.45 -0.47  16.02 17.57  21.01  -2.96  0.37  -0.22  17.20  MEAN ± S.E.  20.44 ±2.42  -4.63 ±3.53  0.35 ±0.05  -0.23 ±0.03  16.45 ±1.23  12.13 ±1.98  -1.23 ±3.90  0.23 ±0.05  -0.10 ±0.03  13.10 ±0.94  TABLE XLIV:  -20.96  Experiment 3: P e r m e a b i l i t y Data And Volumes F o r F o r Each P e r i o d : I.V. 15M 0.6 pg/Kg/Hr.  104  RECOVERY PERIOD  DAMAGE PERIOD NIF  DOG 14  15  17  H  Na  -8.73  0.37  -0.18  15.80  0.33  -0.15  12.94  -6.62  0.33  -0.15  13.42  15.11  -4.59  0.32  -0.12  10.02  16.96 9.87  31.82  -0.55  0.53  -0.26  21.03  -0.17 0.23  13.33 12.80  15.65  -5.11  0.32  -0.16  10.48  -0.22 ±0.02  12.99 ±0.85  16.95 ±1.75  -5.97 0.37 ±1.39 ±0.03  -0.17 ±0.02  13.94 ±1.65  Na  H  Na  16.30 11.44  3.93 -11.07  0.29 0.28  -0.16 -0.15  20.24 11.52  16.00  9.39 17.73  -16.56 -9.26  0.24 0.39  -0.18 -0.19  11.41 11.66  14.96  12.67 18.80  -9.21 -12.91  0.25 0.44  -0.18 -0.20  14.27 11.47  14.41  14.10 17.55  -16.10 -12.32  0.29 0.38  -0.24 -0.23  12.28 10.12  30.29 22.94  -12.37 -22.32  0.51 0.53  -0.35 -0.34  0.35 0.43  14.97 19.00 MEAN ± S.E.  Volume ml/Hr  H  Na  -8.00 -12.30  17.09 -11.53 0.36 ±1.60 ±1.80 ±0.30  TABLE XLV:  K  NIF yeq/min  K  ueq/min  -10.24  Experiment 3: P e r m e a b i l i t y Data And Volumes F o r Each Pouch: Metiamide 3 mg/Kg/Hr.  105  BIBLIOGRAPHY  1.  G o l d b l a t t MW. Ind.  2.  A Depressor substance i n seminal  Bergstrom S, S j o v a l l J .  The i s o l a t i o n o f p r o s t a g l a n d i n E from sheep  A c t a . Chem. Scand. 14: 1701-1705, 1960.  Bergstrom S, Ryhage R, Samuelsson B, S j o v a l l J . p r o s t a g l a n d i n E , F^, F  4.  J . Soc. Chem.  (London) 52: 1056-1057, 1933.  prostate glands.  3.  fluid.  Karim SMM.  2 a  '  A c t a  «  The s t r u c t u r e o f  Chem. Scand. 16: 501-502, 1962.  E f f e c t s of o r a l administration o f prostaglandins  on the human u t e r u s .  and  J . Obst. and Gynaec. B r . Commonwealth. 78: 289-293,  1971.  5.  Hart SL. tine.  6.  The a c t i o n s o f p r o s t a g l a n d i n s E^ and F  2  a  on human f e t a l i n t e s  B r . J . Pharmac. 50: 159-160, 1974.  F l e s h i e r B, Bennett A.  Responses o f human, g u i n e a p i g and r a t c o l o n i c  c i r c u l a r muscle t o p r o s t a g l a n d i n s .  J . Lab. and C l i n . Med. 74: 872-873,  1969.  7.  Bergstrom S, E u l e r USv. E  8.  , and E .  The b i o l o g i c a l a c t i v i t y o f p r o s t a g l a n d i n E ,  Acta. Physiology  Scand. 59: 493-494, 1963.  Robert, A, Nezamis J E , P h i l l i p s J P . prostaglandins.  I n h i b i t i o n o f g a s t r i c s e c r e t i o n by  Amer. J . D i g . D i s . 12: 1073-1076, 1967.  106  9.  P i e r c e NF,  C a r p e n t e r CCJ,  E l l i o t HL,  g l a n d i n s , t h e o p h y l l i n e and  cholera exotoxin  and e l e c t r o l y t e movement i n canine 22-32,  10.  jejunum.  Moncada S, Higgs EA,  Karim SMM,  Vane JR.  Gastroenterology  13.  Sharma SD.  Therapeutic  Gyaec. Br. Commonwealth 78:  F i l s h i e GM.  abortion.  Br. Med.  O l l e y PM,  C o c e a n i F.  The  a b o r t i o n and  Cohen MM,  15.  Fung WP,  i n d u c t i o n of labour  2  2  Fung WP,  10-12,  Karim SMM,  prostaglandin Ann.  F  2 a  '  Tye  E^.  J  *  prostaglandins  for therapeutic  1970.  Br. Heart J . 38:  877,  heart  1976.  preparation.  CY.  E f f e c t of 15(R)-15-methyl  prostaglandin  C o n t r o l l e d endoscopic  CY.  Double b l i n d t r i a l  o f 15(R)-15-methyl  E^ methyl e s t e r i n the r e l i e f of p e p t i c u l c e r p a i n .  Acad. Med.  °kst.  1974.  Tye  3: 375,  by  1971.  methyl e s t e r on h e a l i n g g a s t r i c u l c e r s .  Lancet i i :  16.  of E  E^ and  Emergency treatment o f c e r t a i n c y a n o t i c  B o l t o n JP, In  Karim SMM,  use  294-300,  J . 3: 198-200,  defects with prostaglandin  14.  aggregation.  1977.  Karim SMM,  E  60:  venous t i s s u e s generate  i n h i b i t o r of p l a t e l e t  the i n t r a v a g i n a l a d m i n i s t r a t i o n of p r o s t a g l a n d i n s  12.  prosta  upon t r a n s m u c o s a l water  Human a r t e r i a l and  ( p r o s t a g l a n d i n X), a p o t e n t  Lancet i : 18-20,  and  E f f e c t s of  1971.  Prostacylin  11.  Greenough WB.  1974.  study.  107  17.  Bennett A.  P r o s t a g l a n d i n and the A l i m e n t a r y  P h y s i o l o g i c a l , Pharmacological (Ed.), MTP P r e s s  18.  Tract.  In: Prostaglandin:  and P a t h o l o g i c a l A s p e c t s .  L t d . Lancaster,  SMM  England, pp 247-276, 1976.  Bennett A, Murray JG, W y l l i e JH.  Occurrance o f p r o s t a g l a n d i n  human stomach, and a study o f i t s e f f e c t on human i s o l a t e d muscle.  19.  in  gastric  B r . J . Pharmac. Chemother. 32: 339-349, 1968.  Newman A, DeMoraes - F i l JPP, P h i l i p p a k o s D, M i s i e w i c z J J . The E f f e c t of i n t r a v e n o u s functions.  20.  Karim  Karim SMM,  i n f u s i o n o f p r o s t a g l a n d i n E^ and F  on human g a s t r i c  Gut 16: 272-276, 1975.  C a r t e r DC, Bhana D, Ganesan PA.  Effect of o r a l l y  administered  p r o s t a g l a n d i n E^ and i t 15-methyl analogues on g a s t r i c s e c r e t i o n . Br. Med. J . 1: 143-146, 1973.  21.  Robert A, P h i l l i p s JP, Nezamis J E . g a s t r i c s e c r e t i o n i n the dog.  22.  Gastroenterology,  Robert A, S c h u l t z JR, Nezamis J E , L a n c a s t e r and  70:  54: 1263, 1968.  C.  Gastric antisecretory  a n t i u l c e r p r o p e r t i e s o f PGE , 15 methyl PGE , 2  Intravenous,  23.  I n h i b i t i o n by p r o s t a g l a n d i n E ^ o f  2  16.16-dimethyl  o r a l , and i n t r a j e j u n a l a d m i n i s t r a t i o n .  potent 1973.  BJ.  15-methyl PGE  2  inhibitors of gastric secretion.  and 16.16-dimethyl Adv. B i o s c i .  2>  Gastroenterology  359-370, 1976.  Robert A, M a g e r l e i n  PGE  PGE : 2  9: 247-253,  1G8  24.  Robert A.  Prostaglandins  and the D i g e s t i v e System. In : Les P r o s t a g l a n d i n e s .  Symposium Oct. 4-6, 1977, P a r i s , pp. 297-315.  25.  Wada T, I s h i j a w a M. gastric secretion.  26.  E f f e c t s of prostaglandins  J a p . J . C l i n . Med. 28: 2465-2468  Karim SMM, C a r t e r DC, Bhana D, Ganesan PA. intravenously administered  (In J a p a n e s e ) .  The e f f e c t o f o r a l l y and  p r o s t a g l a n d i n 16.16-dimethyl E ^ methyl e s t e r  as human g a s t r i c a c i d s e c r e t i o n .  27.  on t h e f u n c t i o n o f the  Prostaglandins  Konturek S J , K w i e c i e n N, Swierczek J , Olesky  4: 71-83, 1973.  J , S i t o E, Robert A.  Comparison of m e t h y l a t e d p r o s t a g l a n d i n E ^ analogs g i v e n o r a l l y i n t h e i n h i b i t i o n o f g a s t r i c responses t o p e n t a g a s t r i n and peptone meal i n man. Gastroenterology,  28.  Robert A.  70: 683-687, 1975.  Antisecretory prostaglandins  h y p e r s e c r e t i o n and p e p t i c u l c e r . Vol. I l l ,  29.  i n the t r e a t m e n t o f g a s t r i c  In: Progress  i n Gastroenterology.  G.B. J e r s y G l a s s , Ed. (In P r e s s ) .  D a t u r i S, F r a n c e s c h i n i J , M a n d e l l i V, M i z z o t t i B, U s a r d i MM. r o l e f o r PGE^ i n t h e g e n e s i s  A proposed  of stress-induced g a s t r i c u l c e r s .  Br. J .  Pharmac. 52: 464 P, 1974.  30.  Robert A, S t a n d i s h WH. i n j e c t i o n of histamine.  Production F e d . Proc.  o f duodenal u l c e r s i n r a t s , w i t h one 32: 322, 1973.  109  31.  Mann NS, Sachdev A.  Prevention of A s p i r i n , Ketoprofen  and Ibuprofen  induced acute e r o s i v e g a s t r i t i s by metiamide and c i m e t i d i n e .  Gastro  e n t e r o l o g y 70: 914, 1976.  32.  F o s t e r LD, S a f a i e - S h i r a z i S. experimental  A.  stress  Personal  ulcers.  E f f e c t o f metiamide i n p r e v e n t i o n o f  Surg. Form 26: 360-361, 1975.  33.  Robert  Communication.  34.  Davenport HW, Warner HA, Code CF. mucosal b a r r i e r t o sodium.  35.  Davenport HW. acids.  36.  of gastric  G a s t r o e n t e r o l o g y 47: 142-152, 1964.  mucosal i n j u r y by f a t t y and a c e t y l s a l i c y l i c  G a s t r o e n t e r o l o g y 46: 245-253, 1964.  T e o r e l l T.  On t h e p e r m e a b i l i t y o f t h e stomach f o r a c i d s and some o t h e r  substances.  37.  Gastric  Functional significance  Smith B.M.  J . Gen. P h y s i o l 16: 59, 1939.  S k i l l m a n J J , Edwards BG, S i l e n W.  g a s t r i c mucosa.  Alteration  P e r m e a b i l i t y o f t h e human  by a c e t y l s a l i c y l i c a c i d and e t h a n o l .  New E n g l . J . Med. 285: 716-721, 1971.  38.  Chvasta  TE, Cooke AR.  The e f f e c t o f s e v e r a l u l c e r o g e n i c drugs on the  canine g a s t r i c mucosal b a r r i e r .  39.  Davenport HW. and u r e a .  J . Lab. C l i n . Med. 79: 302-315, 1972.  D e s t r u c t i o n o f the g a s t r i c mucosal b a r r i e r by d e t e r g e n t s  Gastroenterology  54: 175-181, 1968.  110  40.  41.  Davenport HW.  E t h a n o l damage t o canine  Proc. Soc Exp.  B i o l . Med.  S k i l l m a n J , Gould SA, C l i n i c a l and  Ann.  42.  S k i l l m a n J , S i l e n W.  43.  Munro DR.  g a s t r i c mucosal b a r r i e r :  564-584,  Stress Ulcers.  ill  and normal man  1970.  Lancet  ii:  1303-1306,  1972.  I n h i b i t i o n o f p r o s t a g l a n d i n s y n t h e s i s as a mechanics o f a c t i o n  Glyglewski  238:  Hamberg M.  Cohen, MM.  Nature  (New  1974.  Biol.)  231:  232-235,  Herbaczynska-Cedro K, Vane JR.  drugs on p r o s t a g l a n d i n b i o s y n t h e s i s .  104-106,  of  Nature  (New  1972.  Commun. 49:  720-726,  876,  C a r t e r DC.  g a s t r i c mucosal b a r r i e r .  Biochem.  1972.  P r o s t a g l a n d i n E^ p r e v e n t s 68:  1971.  Effects  I n h i b i t i o n o f p r o s t a g l a n d i n s y n t h e s i s i n man.  Gastroenterology  O'Brien PE,  R,  960-972,  gastropathy  Vane JH.  Flower R,  66:  and  Gastroenterology  Biophys, Res.  48.  The  i n dogs.  Biol)  47.  S i l e n W.  Route o f p r o t e i n l o s s d u r i n g a model p r o t e i n l o s i n g  anti-inflammatory  46.  1967.  studies i n c r i t i c a l l y  Surg. 172:  f o r a s p i r i n l i k e drugs.  45.  657-662,  Chung RSK,  experimental  i n the r a b b i t .  44.  126:  o x y n t i c g l a n d u l a r mucosa.  g a s t r i c mucosal b a r r i e r damage.  1975.  E f f e c t o f g a s t r i c s e c r e t o r y i n h i b i t o r s on Gut  16: 437-442,  1975.  the  49.  B o l t o n J P , Cohen MM.  P e r m e a b i l i t y e f f e c t s o f E^ p r o s t a g l a n d i n s on  canine g a s t r i c mucosa.  50.  Robert  Gastroenterology  A, Nezamis J E , P h i l l i p s JP.  70: 865, 1976.  E f f e c t o f p r o s t a g l a n d i n E^ on  g a s t r i c s e c r e t i o n and u l c e r f o r m a t i o n i n the r a t .  Gastroenterology  55:  481-487, 1968.  51.  Fung WP,  Lee SK, Karim SMM.  E f f e c t o f p r o s t a g l a n d i n 15(R)-15-methyl-  E^-methyl e s t e r on the g a s t r i c mucosa i n p a t i e n t s w i t h p e p t i c u l c e r a t i o n - an endoscopic  52.  Dean ACB.  and h i s t o l o g i c a l study.  P r o t e c t i v e e f f e c t o f carbenoxolone  the stomach. Carbenoxolone Sodium. (Ed.) London; B u t t e r w o r t h s ,  53.  Whiteman P.  J . Physiol.  A method o f q u a n t i t a t i v e e s t i m a t i o n of (Lond.) 242: 116-117, 1974.  i n mine  Biochem. J . 121: 251-257, 1973.  Chung RSK, F i e l d M, S i l e n W. and l i t h i u m .  A Symposium, JM Robson; FM S u l l i v a n  The q u a n t i t a t i v e d e t e r m i n a t i o n o f glycoaminoglycans  w i t h A l c i a n Blue 8GX.  55.  i n drug i n d u c e d l e s i o n s o f  pp. 33-39, 1968.  Corne S J , M o r r i s s e y SM, Woods RJ. g a s t r i c b a r r i e r mucus.  54.  P r o s t a g l a n d i n s 5: 465-472, 1974.  P e r m e a b i l i t y o f g a s t r i c mucosa o f hydrogen  G a s t r o e n t e r o l o g y 64: 593-598, 1973.  56.  Ivey KJ.  G a s t r i c mucosal b a r r i e r .  57.  P i p e r DW,  Whitecross  D, Leonard  properties of g a s t r i c j u i c e .  G a s t r o e n t e r o l o g y 61: 247-257, 1971.  P., C l a r k e A.  Gastroenterology  A l c i a n Blue b i n d i n g 59: 534-538, 1970.  Malawer S J , Powell DW.  An improved t u r b i d i m e t r i c a n a l y s i s o f p o l y e t h y l e n e  g l y c o l u t i l i z i n g an e m u l s i f i e r .  Hyd£n S.  Gastroenterology  53: 250-256, 1967.  A t u r b i d i m e t r i c method f o r the d e t e r m i n a t i o n o f h i g h e r p o l y e t h y l e n e  glycols i n b i o l o g i c a l materials.  Ann. Roy. A g r i c . C o l l . Sweden 22:  139-145, 1955.  Grossman MI, Konturek S J .  I n h i b i t i o n o f a c i d s e c r e t i o n i n dogs by  metiamide, a h i s t a m i n e a n t a g o n i s t a c t i n g on H ^ - r e c e p t o r s .  Gastroenterology  66: 517-521, 1974.  H o l l a n d e r F.  The e l e c t r o l y t e p a t t e r n o f g a s t r i c mucinous  Its implication f o r c y s t i c f i b r o s i s .  secretions:  Ann N.Y. Acad. S c i . 106: 757-766,  1963.  A l t a m i r a n o M.  A l k a l i n e s e c r e t i o n s produced by i n t r a - a r t e r i a l  acetylcholine.  J . P h y s i o l . 168: 787-803, 1963.  Fromm D, Fuhro R.  A c t i v e b i c a r b o n a t e s e c r e t i o n by mammalian antrum.  Surg. Forum 27: 437-440, 1976.  Jacobson ED.  Comparison o f p r o s t a g l a n d i n E ^ and n o r e p i n e p h r i n e  g a s t r i c mucosal c i r c u l a t i o n .  on the  P r o c . Soc. exp. B i o l . Med. 133: 516-519,  1970.  W i l s o n DE, L e v i n e RA.  E f f e c t o f p r o s t a g l a n d i n E ^ on canine g a s t r i c a c i d  s e c r e t i o n and g a s t r i c mucosal b l o o d flow. 1972.  Amer. J . D i g . D i s . 17: 527-532,  113  66.  Main IHM,  W h i t t l e SJR.  mucosal b l o o d 428-436,  67.  Kuo  e f f e c t s o f E and A p r o s t a g l a n d i n s on  a c i d s e c r e t i o n i n the r a t .  B i . J . Pharmac.  Mechanism o f a c t i o n o f a s p i r i n on canine  Amer. J . P h y s i o l . 230:  Jacobson ED,  Chaudhury TK,  762-767,  Thompson WJ.  c y t o p r o t e c t i o n by p r o s t a g l a n d i n s .  69.  gastric 49:  1973.  Y-J, Shanbour LL.  mucosa.  68.  flow and  The  MacDonald AS,  1976.  Mechanism o f g a s t r i c mucosal  Gastroenterology  S t e e l e BJ, Bottomley MC.  gastric  Treatment o f  upper g a s t r o i n t e s t i n a l haemorrhage w i t h metiamide.  70:  897,  1976.  stress-induced Lancet  i : 68-70,  1976.  70.  Dudley HAF, Lancet  F i e l d i n g LP,  i : 481,  1977.  G l a z e r G.  Gastroduodenal r e b l e e d i n g on  cimetidine  APPENDIX  C o n f i r m a t i o n o f the E f f e c t i v e n e s s o f the Metiamide used i n Experiment 3  An experiment was performed i n two dogs t o e s t a b l i s h t h a t the b a t c h of metiamide used was  e f f e c t i v e as an i n h i b i t o r o f a c i d  An i n f u s i o n o f h i s t a m i n e d i - H C l , 50 ug/Kg was  secretion.  g i v e n t o two dogs over  105 minutes, the mean 15 minute a c i d o u t p u t s a r e r e c o r e d as the l i n e i n F i g u r e 8.  In a subsequent experiment the same dogs were s u b j e c t e d  t o the same i n f u s i o n o f h i s t a m i n e but metiamide from 60-120 minutes. output i n t h i s  3 mg/Kg/hour was  infused  The broken l i n e i n d i c a t e s the mean 15 minute  acid  experiment.  The b a t c h o f metiamide was effect.  solid  c o n s i d e r e d normal i n i t s a n t i s e c r e t o r y  Metiamide 3 mgs/kg/hr I.V.  Time in minutes  FIGURE 8:  I l l u s t r a t e s the i n h i b i t o r y e f f e c t o f i n t r a v e n o u s metiamide on h i s t a m i n e s t i m u l a t e d a c i d o u t p u t from a H e i d e n h a i n pouch. In b o t h experiments a c o n s t a n t i n f u s i o n o f h i s t a m i n e d i - H C l 50 yg/Kg/Hr was g i v e n from 15 t o 120 m i n u t e s . The d o t t e d l i n e i n d i c a t e s the e f f e c t o f metiamide 3 mgs/Kg/Hr from 60 t o 120 minutes.  116  2.  E f f e c t o f D i l u t i o n o f A l c i a n Blue B i n d i n g  An experiment was performed of 1 ml. o f g a s t r i c results  i n which the e f f e c t o f s e r i a l  j u i c e on A l c i a n Blue b i n d i n g was s t u d i e d .  dilutions The  (Table XLVI) i l l u s t r a t e t h a t the d i f f e r i n g volumes o f g a s t r i c  j u i c e a r e n o t l i k e l y t o have i n t r o d u c e d a s i g n i f i c a n t e r r o r .  ±1/  DILUTIONS  TABLE XLVI:  ALCIAN BLUE BOUND mg/ml  1 ml.  0.14  2 ml.  0.07  4 ml.  0.04  8 ml.  0.01  E f f e c t of s e r i a l d i l u t i o n s of 1 ml. o f g a s t r i c j u i c e on A l c i a n Blue b i n d i n g .  

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