Open Collections

UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

The role of catecholamines in erythrocyte pH regulation and oxygen transport in rainbow trout (Salmo… Primmett, Dennis R. N. 1984

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-UBC_1984_A6_7 P75.pdf [ 1.89MB ]
Metadata
JSON: 831-1.0096135.json
JSON-LD: 831-1.0096135-ld.json
RDF/XML (Pretty): 831-1.0096135-rdf.xml
RDF/JSON: 831-1.0096135-rdf.json
Turtle: 831-1.0096135-turtle.txt
N-Triples: 831-1.0096135-rdf-ntriples.txt
Original Record: 831-1.0096135-source.json
Full Text
831-1.0096135-fulltext.txt
Citation
831-1.0096135.ris

Full Text

THE ROLE OF CATECHOLAMINES IN ERYTHROCYTE pH REGULATION AND OXYGEN TRANSPORT IN RAINBOW TROUT (Salmo gairdneri) DURING AND FOLLOWING EXHAUSTIVE ACTIVITY by DENNIS R. N. PRIMMETT A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES (The Department of Zoology) We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA May 1984 © Dennis R. N. Primmett, 1984 In presenting t h i s thesis i n p a r t i a l f u l f i l m e n t of the requirements for an advanced degree at the University of B r i t i s h Columbia, I agree that the Library s h a l l make i t f r e e l y available for reference and study. I further agree that permission for extensive copying of t h i s thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. I t i s understood that copying or publication of t h i s thesis for f i n a n c i a l gain s h a l l not be allowed without my written permission. Department of 'Z.&Ql—O&t. The University of B r i t i s h Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3 DE-6 (3/81) i i ABSTRACT The r o l e of endogenous plasma catecholamines i n erythrocyte pH regulation and blood oxygen transport in freshwater rainbow trout (Salmo  gair d n e r i ) was examined. The f i s h were subjected to anaerobic exercise followed by aerobic exercise at 80% of t h e i r c r i t i c a l swimming v e l o c i t y . The anaerobic exercise was found to r e s u l t i n a substantial e x t r a c e l l u l a r a c i d o s i s , increased plasma catecholamine concentrations, increased blood oxygen l e v e l s , and increased e r y t h r o c y t i c pH. The t r a n s i t i o n from anaerobic to near-maximal aerobic exercise seemed to produce a temporary unsteady 6tate in the v e n t i l a t i o n / p e r f u s i o n properties of the oxygen uptake system; however, a new steady state was achieved within one hour of aerobic recov-ery. Anaerobic exercise followed by propranolol treatment resulted i n a s i g n i f i c a n t decrease i n e r y t h r o c y t i c pH concurrent to the e x t r a c e l l u l a r a c i d o s i s but blood oxygen l e v e l s were unchanged; i t was assumed that the lack of a Root e f f e c t during red c e l l a c i d o s i s was due to secondary e f f e c t s of propranolol on erythrocytes. I t was concluded that adrenergic regulation of red c e l l pH i n freshwater rainbow trout allowed normal haemoglobin-oxygen carriage during plasma acid-base disturbances r e s u l t i n g from stren-uous exercise. i i i TABLE OF CONTENTS Abstract i i L i s t of Tables i v L i s t of Figures v Acknowledgements v i Chapter I. The E f f e c t s of Burst Exercise on Subsequent Oxygen Transport In Rainbow Trout 1 Introduction 2 Methods and Materials 6 Experimental Animals 6 Exercise Performance Assessment 6 Experimental Procedure 6 Experimental Analysis .. 7 Results 9 Discussion 22 Chapter I I . The E f f e c t of Anaerobic Exercise Followed by Adrenergic Blockade i n Rainbow Trout 26 Introduction 27 Methods and Materials 28 Experimental Animals 28 Experimental Procedure 28 Blood Analysis • 29 Results 3 0 Discussion 3 ^ References 3 ^ iv LIST OF TABLES Table 1. Effects of burst exercise and subsequent aerobic exercise at 80% Ucrit in rainbow trout 21 Table 2. Effects of bur6t exercise followed by 6ha_ injection (EX) and burst exercise followed by propranolol injection (EXP) in rainbow trout 33 V LIST OF FIGURES Figure 1. Relationship between plasma hydrogen ion and lactate levels In trout during a burst swim and an ensuing aerobic swim at 80% Ucrit 12 Figure 2. Relationship between plasma adrenaline, noradrenaline and dopamine levels in trout during a burst swim and an ensuing aerobic swim at 80% Ucrit 14 Figure 3. Effect of a burst swim and an ensuing aerobic swim at 80% Ucrit in trout on whole blood pH and red c e l l pH 16 Figure 4. Effect of a burst swim and an ensuing aerobic swim at 80% Ucrit in trout on haematocrit (Hct), blood haemoglobin concentration (Hb), and mean cellular haemoglobin concentration (MCHC) 18 Figure 5. Effect of a burst swim and ensuing aerobic swim at 80% Ucrit on art e r i a l oxygen content (CaO^), the amount of oxygen bound to haemoglobin in arte r i a l blood (C A U 2)» art e r i a l oxygen tension (Pa0 2), and ventilatory frequency (V f) 20 Figure 6. The effect of propranolol treatment following burst exercise on extracellular and erythrocytic pH 32 v l ACKNOWLEDGEMENTS I would l i k e to express my gratitude to the following people f o r t h e i r help with t h i s t h e s i s : Dr. D. J . Randall, who suggested and supervised t h i s project and provided the laboratory space and equipment; Dr. R. G. B o u t i l i e r , who as s i s t e d me i n the experiments outlined i n the second chapter of t h i s t h e s i s ; Mrs. Janet Lynne Primmett, my wife and patient research a s s i s t a n t , whose help and encouragement i s most s i g n i f i c a n t . 1 CHAPTER I THE EFFECTS OF BURST EXERCISE ON SUBSEQUENT OXYGEN TRANSPORT IN RAINBOW TROUT 2 INTRODUCTION Exercise i n f i s h can be broadly c l a s s i f i e d into two categories: ( i ) aerobic a c t i v i t y , where metabolic requirement equals supply and end-product formation i s compensated by disposal (Brett 1964, 1972; Beamish 1978), ( i i ) anaerobic or burst a c t i v i t y , where exercise i s quickly t e r -minated due to depletion of i n t r a c e l l u l a r glycogen reserves (Beamish 1978) or build-up of metabolic end-products (Hochachka 1961). When the a c t i v i t y exceeds the anaerobic threshold ATP i s produced by g l y c o l y t i c degradation of stored muscle glycogen (Nakatani 1957, Driedzic & Hochachka 1975) which r e s u l t s i n an 0^ debt that i s repaid following burst exercise (Brett 1964). Burst swimming induces s u b s t a n t i a l acid-base, r e s p i r a t o r y and e l e c t r o l y t e perturbations i n salmonids (for review see H e i s l e r 1980). During aerobic a c t i v i t y , f i s h p r e f e r e n t i a l l y u t i l i z e highly perfused red muscle; however, during burst exercise white muscle i s r e c r u i t e d . The white muscle i s poorly perfused and i t s a c t i v i t y necessitates anaerobic metabolism r e s u l t i n g i n l a c t i c a c i d production (Heisler 1980). L a c t i c acid i s the most Important g l y c o l y t i c metabolite and i s produced under a v a r i e t y of conditions of ti s s u e anoxia; i t i s almost completely diss o c i a t e d at p h y s i o l o g i c a l pH (pK 3.9) into s t o l c h i o m e t r l c a l l y equivalent quantities of l a c t a t e ions (La~) and metabolic protons (H +) (Heisler 1980). Wardle (1978) has estimated that up to 84 mMol l a c t i c acid per Kg white muscle can be produced during severe exercise. Both d i s s o c i a t i o n products d i f f u s e from the muscle c e l l 6 into the e x t r a c e l l u l a r space with the H + load having pronounced e f f e c t s on blood acid-base status. Powers (1980) has suggested that there should be adaptive advan-tage f o r pelagic f i s h ( l i k e salmonids) to minimize acid loading i n the blood following burBt exercise so that post-burst acope f o r a c t i v i t y i s not impaired. I t i s the aim of t h i s study to examine i n rainbow trout the e f f e c t of a burst swim upon an ensuing period of aerobic exercise. The post-burst l e v e l of aerobic a c t i v i t y to be used i s 80% of the c r i t i c a l •wimming v e l o c i t y (802 U c r i t ; Brett 1964) since there i s much evidence that aerobic metabolism p r e v a i l s i n salmonids at 80% U c r i t (for review see Randall 1970 , Jones & Randall 1978, Randall & Daxboeck 1979, Randall 1982) For example, d i s c o n t i n u i t i e s i n the r e l a t i o n between 0. uptake (Mn ) and 2 °2 swimming v e l o c i t y (U) suggest anaerobic contributions to aerobic exercise and i f such was the case then more than one group of muscles would be u t i l -ized during the a c t i v i t y period (Jones & Randall 1978). I t has been shown that below U c r i t , *L Increases exponentially with U (Brett 1964) and that 2 no e l e c t i c a l a c t i v i t y i s recorded from white muscle at speeds up to 80% U^^ (Bone e£ a_l 1978) . Investigations of gas exchange l n f i s h have centered on 0^ and CO transport across the g i l l s (for review see Krogh 1941, Fry 1957, Hughes & Shelton 1962, Randall 1970 , Randall 1982); i n contrast, gas tr a n s f e r from g i l l s to t i s s u e s has not been studied i n much d e t a i l i n f i s h . The 0^ carry-ing capacity (OjCC) v a r i e s between species (Ruud 1954, Holeton 1968). Blood haemoglobin (Hb) and haematocrit (Hct) l e v e l s increase i n f i s h i n response to exercise (Kiceniuk & Jones 1977) so that O^CC r i s e s to meet increased metabolic demands ; cardiac output (Q) increases to 2.4 times i t s re s t i n g value at 80% U c r i t i n salmonids (Kiceniuk & Jones 1977). Therefore o v e r a l l 0 2 transport to the ti s s u e s i s elevated during aerobic exercise. Swimming at 80% U c r i t induces considerable demands on f i s h r e s p i r atory systems. At these a c t i v i t y l e v e l s 0^ consumption (V Q ) i s greatly elevated (and i s r e f l e c t e d by a 2-3 times Increase i n arterio-venous 0^ content difference) and t h i s i s associated with an Increase i n M (to 12 4 t i n e s the r e s t i n g l e v e l ) (for review see Jones & Randall 1978). In order to increase M_ and Q ,branchial and coronary musculature must increase t h e i r 2 power output which i n turn elevates t h e i r own V Q causing even greater demands on the o v e r a l l r e s p i r a t o r y system (Jones 1971). Therefore any d i s -turbance or i n h i b i t i o n of these cardiovascular and r e s p i r a t o r y adjustments would be expected to l i m i t the Bcope for aerobic a c t i v i t y . Blood 0 2 content does not show a l i n e a r r e l a t i o n s h i p with 0^ ten-sion; 02 content changes with the slope of the 0^ d i s s o c i a t i o n curve ( see Randall 1970 ). This slope i s affected by blood pH, C0 2 tension, temperature and organic phosphate l e v e l s . In t e l e o s t blood, increased C0 2 content or decreased pH (in v i t r o ) causes not only a f a l l i n Hb-0 2 a f f i n i t y (Bohr e f f e c t ) but also a decrease i n 0 2CC (Root e f f e c t : a f a l l i n 0 2 content even at atmospheric 0 2 tension) (6ee Randall 1970 , Riggs 1970). Chemically, the Root e f f e c t i s a c t u a l l y an enhanced version of the a l k a l i n e Bohr e f f e c t (for review see Riggs 1970, Bartels & Baumann 1977, Perutz & Brunori 1982) but f u n c t i o n a l l y the e f f e c t s d i f f e r . Since burst swimming Induces an e x t r a c e l l -u l a r a c i d o s i s one might expect that a Root e f f e c t would occur i n a r t e r i a l blood; such an e f f e c t would l i m i t tissue 0 2 u t i l i z a t i o n and hence aerobic capacity subsequent to the anaerobic a c t i v i t y . Recently i t has been reported that adrenaline (AD) can abolish the Bohr e f f e c t i n trout red c e l l s ^n v i t r o during an e x t r a c e l l u l a r acidosis by regulating e r y t h r o c y t i c pH (Nikinmaa 1983). Catecholamines are known to be released into the c i r c u l a t i o n of f i s h i n response to s t r e s s (Mazead & Mazeaud 1981). In p a r t i c u l a r , AD has been shown to Increase g i l l blood flow, g i l l membrane permeability and lamellar recruitment (see Randall 1982 for review) and therefore l i k e l y plays a r o l e i n the elevation of Mg with exercise. Since c i r c u l a t i n g Hb l e v e l s are higher with aerobic exercise, the increased M would elevate 0, transport to the tissues i f 0-CC was not i n h i b i t e d by 5 a Root e f f e c t . I t i s the hypothesis of t h i s study that catecholamines are released into trout blood during a burst swim and act to maintain red c e l l pH, i n the face of a f a l l i n whole blood pH, circumventing a Root e f f e c t such that the aerobic scope f o r post-burst a c t i v i t y Is not c u r t a i l e d . 6 METHODS AND MATERIALS Experimental animals Rainbow trout (Salmo g a i r d n e r i ) . of both sexes, were obtained from the Sun Va l l e y Trout Farm (Mission, B.C.) and were kept i n moving, dechorinated Vancouver tap water (5.0-15.0 °C) f o r at l e a s t 4 weeks p r i o r to measuring exercise performance (Gray 1953,1957; Brett et a_l 1958; Hammond & Hickman 1966). The trout were anaesthetized with MS222 (1:10000,pH 7.5) and implanted with chronic dorsal a o r t i c cannulae (heparlnized Clay-Adams PE60 polyethylene tubing) i n a manner s i m i l a r to Smith and B e l l (1964). Exercise performance assessment A Brett (1964) respirometer was used to assess the exercise per-formance of t r o u t . A d e t a i l e d d e s c r i p t i o n of t h i s respirometer can be found elsewhere (Kiceniuk 1975). Following the cannulation procedure, the f i s h were allowed to recover in the respirometer f o r 18 hr at a water v e l o c i t y of 1.0 body length per second (1-0 BL/sec) a f t e r which time the swimming performance of the animals was assessed i n the respirometer by the c r i t i c a l v e l o c i t y swimming test (Brett 1964). D e t a i l s of t h i s test are given by Beamish (1978); i n t h i s study, the v e l o c i t y increment was 0.2 BL/sec and the prescibed period of swimming was 60 min. A f t e r the c r i t i c a l swimming v e l o c i t y was determined, the swimming v e l o c i t y was returned to 1.0 BL/sec. Experimental Procedure Subsequent to 18 hr of aerobic recovery from exercise performance assessments, various blood v a r i a b l e s were measured under 3 d i f f e r e n t but successive conditions of a c t i v i t y : 7 (1) RESTING AEROBIC LEVEL ( l e . the trout were swum at 1.0 BL/sec f o r 18 hr before the r e s t i n g blood sample was taken) (2) IMMEDIATE END-BURST ANAEROBIC LEVEL ( i e . following the r e s t i n g l e v e l determination, the f i s h were swum at 120% of the c r i t i c a l swimming v e l o c i t y (Ucrit) u n t i l exhaustion was apparent, at which time t h i s sample was taken) (3) POST-BURST AEROBIC LEVEL ( i e . following the end-burst l e v e l determination, the f i s h were swum at 80% U c r i t and samples taken at 15 min, 1 hr, and A hr post-burst). Experimental analysis The volume of each blood sample was e i t h e r 500 uL or 100 uL depending upon the p r o t o c o l . This blood was replaced with Cortland s a l i n e (Wolfe 1963) that had been p r e - e q u i l i b r a t e d with p h y s i o l o g i c a l gas tensions ( P n -120 t o r r , P r n -1 t o r r ) . °2 C 0 2 PROTOCOL I: At each sampling time, 500 uL of whole blood was removed from the f i s h . A r t e r i a l 0^tension (PaO^) and whole blood pH (pHe) were measured on whole blood using a Radiometer PHM-71 acid-base analyzer and associated micro-pH and 0^ electrodes. The remaining whole blood was then centrifuged In a Brinkman 3200 centrifuge and the plaBma f r a c t i o n was separated from the red c e l l (RBC) f r a c t i o n . 50 uL of plasma was mixed with 100 uL of i c e cold 8% p e r c h l o r i c aci d and centrifuged In the Brinkman 3200 centrifuge; the r e s u l t i n g supernatant was assayed (Sigma) f o r l a c t a t e (La") content. The remaining plasma was assayed f o r catcholamine content ( l e . adrenaline (AD), noradrenaline (NA), dopamine (DOPA) ) using high pressure l i q u i d chromatog-raphy ( i e . Spectra-Physics SP8700 de l i v e r y system, BAS electrochemical de-1 8 tector, Ultrasphere ODS column) (aee Woodward 1982). The RBC f r a c t i o n was quick-frozen, i n alcohol and dry-ice and then quick-thawed (Zeidler & Kim 1977) allowing RBC i n t r a c e l l u l a r pH measurements to be taken of the r e s u l t -ing l y s a t e . RBC pH measurements were made using a Radiometer PHM-71 a c i d -base analyzer and micro-pH electrode. V e n t i l a t o r y frequency (V f) was deter-mined v i s u a l l y by counting the number of opercular movements per minute. PROTOCOL II At each sampling time, 100 uL of whole blood was removed from the animal; the smaller blood volume ( c f . PROTOCOL I) was u t i l i z e d i n an attempt to minimize the e f f e c t of sampling ( c f . Jones 1971). 30 uL of whole blood was inje c t e d into a m i c r o c a p i l l a r y tube, centrifuged i n a m i c r o c a p i l l a r y c e n t r i -fuge and the haematocrit (Hct) determined. 20 uL of whole blood was mea-sured for haemoglobin concentration (Hb) using a Perkin-Elmer atomic absorp-tion spectrophotometer ( i e . flame analysis f or iron l e v e l s ; Zetter & Mensch 1967). Mean c e l l u l a r Hb concentration (MCHC) was calculated by d i v i d i n g Hb values with corresponding Hct values (eg. Turner et_ al^ 1983). Plasma 0^ content was calculated (eg. Wood £t i l l 1979) using measured values for PaO^ and values for plasma 0^ s o l u b i l i t y extrapolated from Altman and Dittmer (1971) and corrected for temperature. 20 uL of whole blood was measured fo r t o t a l a r t e r i a l blood 0^ content (Ca0 2 i n v o l s %) using a Lex-0 2~Con oxy-gen content analyzer. Plasma 0 2 content was subtracted from Ca0 2; the r e -maining quantity was divided by corresponding values for Hb giving c a l c u l a -ted values f o r the amount of 0 2 bound to haemoglobin (C^0 2 i n mis 0 2/g Hb). A l l data from the above procedures are given as arithmetic means ± 1 S.E. The s i g n i f i c a n c e of value changes from the r e s t i n g condition (*) was determined using the paired Student's t-Test ( t Q 9 5 ) . 9 RESULTS The e f f e c t of a burst swim and ensuing aerobic swim at 80% U c r i t on plasma H + and La l e v e l s i s i l l u s t r a t e d i n F i g . l . Anaerobic a c t i v i t y causes an immediate r i s e i n both v a r i a b l e s . H + peaks immediately post-burst while La peaks about 1 hr into recovery; however, the t o t a l amount of La~ i n the plasma exceeds H + throughout the recovery period. F i g . 2 shows the e f f e c t s of burst exercise followed by aerobic a c t i v i t y on plasma catecholamine l e v e l s . Exercise has no e f f e c t on DOPA le v e l s i n freshwater rainbow trout. Burst exercise r e s u l t s i n a 35-fold increase i n AD l e v e l s and a 25-fold increase i n NA l e v e l s . During post-burst aerobic exercise, both AD and NA concentrations slowly decrease but s t i l l remain s i g n i f i c a n t l y elevated over r e s t i n g l e v e l s . The e f f e c t of a burst swim and ensuing aerobic swim on pHe and RBC pH i s shown i n Fig.3. Anaerobic a c t i v i t y causes a f a l l i n pHe of about 0.3 pH unit s ; pHe was restored to r e s t i n g l e v e l s a f t e r about 4 hr of aerobic recovery. The exercise-induced f a l l i n pHe did not r e s u l t i n a f a l l i n RBC pH. RBC pH was maintained throughout the anaerobic a c t i v i t y and then was s i g n i f i c a n t l y increased above r e s t i n g l e v e l s from 1 hr to 4 hr into recovery. This data indicates that t h i s exercise protocol i s associated with marked changes to the H + d i s t r i b u t i o n across the red c e l l membrane. F i g . 4 shows the e f f e c t of exhaustive a c t i v i t y followed by aerobic exercise at 80% U c r i t on Hct, Hb, and MCHC. During the burst swim, Hct was increased by about 40%, Hb was increased by about 20%, and MCHC was decreased by about 20%. This data suggests that anaerobic exercise causes about a 40% increase i n the red c e l l f r a c t i o n of whole blood; about % of t h i s r i s e i s due to RBC swelling and the other h i s the r e s u l t of haemoconcentration. The e f f e c t of anaerobic exercise followed by aerobic exercise on 10 Ca0 2, C A0 2, Pa0 2, and V f i s shown i n Fig.5 . Ca0 2 i s maintained during the burst swim, becomes s i g n i f i c a n t l y elevated above r e s t i n g l e v e l s within 1 hr of recovery and then i s restored to r e s t i n g l e v e l s a f t e r 4 hr of recovery. ^A^2* *>a<^2' ^ f B ^ o w sis 1 1* 1 icant decreases from r e s t i n g l e v e l s a f t e r the bur s t swim. C^°2 Pa0 2 are restored to r e s t i n g l e v e l s within 15 min of recovery; Pa0 2 undergoes a temporary overshoot such that t h i s v a r i a b l e i s s i g n i f i c a n t l y elevated over r e s t i n g l e v e l s within 1 hr of recovery. s i g -n i f i c a n t l y overshoots r e s t i n g l e v e l s within 15 min of recovery and then i s restored to r e s t i n g l e v e l s by 1 hr of aerobic recovery. 11 Figure 1. Relationship between plasma hydrogen ion and l a c t a t e l e v e l s in trout during a burst swim and an ensuing aerobic swim at 80% U . ; N=10(lS.E.M.). c r i t Note: R=Rest; Bar=burst a c t i v i t y to exhaustion; 0 hr= s t a r t of post-burst aerobic a c t i v i t y at 80% U c r i t ; *= s i g n i f i c a n t l y d i f f e r e n t from r e s t i n g . 13 Figure 2. Relationship between plasma adrenaline, noradrenaline and dopamine l e v e l s i n trout during a burst swim and an ensuing aerobic swim at 80% U c r i t ; N=8 (±S.E.M.) Note: R=Rest; Bar=burst a c t i v i t y to exhaustion; 0 hr=start of post-burst aerobic a c t i v i t y at 80% U c r i t ; * = s i g n i f i c a n t i y d i f f e r e n t from r e s t i n g . 15 Figure 3. E f f e c t of a burst swim and an ensuing aerobic swim at 80% U ° c r i t i n trout on whole blood pH and red c e l l pH; N=13 (+S.E.M.). Note: R=Rest; Bar=burst a c t i v i t y to exhaustion; 0 0 hr= s t a r t of post-burst aerobic a c t i v i t y at 80% U c r i t ; * = s i g n i f i c a n t l y d i f f e r e n t from r e s t i n g . RED CELL pH WHOLE BLOOD pH ro U> Cn H M 3 M co -v j 00 -4 V O *4 r* 09 U) 17 Figure 4. E f f e c t of a burst swim and ensuing aerobic swim at 80% U c r i t on haematocrlt (Hct), blood haemoglobin concentration (Hb), and mean c e l l u l a r haemoglobin concentration (MCHC); N-6 (±S.E.M.). Note: R=Rest; Bar=burst a c t i v i t y to exhaustion; 0 hr=start of post-burst aerobic a c t i v i t y at 80% U c r i t j * = s i g n i f i c a n t l y d i f f e r e n t from r e s t i n g . 18 19 Figure 5. E f f e c t of a burst swim and ensuing aerobic swim at 80% U c r i t on a r t e r i a l oxygen content (Ca0 2), the amount of oxygen bound to haemoglobin i n a r t e r i a l blood (c 0„), a r t e r i a l oxygen tension A 2 (PaO^), and v e n t i l a t o r y frequency (V^); N=6 f o r + a l l v a r i a b l e s except where N«3 (_S.E.M.). Note: R«Rest; Bar=burst a c t i v i t y to exhaustion; 0 hr=start of post-burst aerobic a c t i v i t y at 80% U c r i t ; * = s i g n i f i c a n t l y d i f f e r e n t from r e s t i n g . TABLE 1.EFFECTS OF BURST EXERCISE AND SUBSEQUENT AEROBIC EXERCISE AT 80* Ucrit IN RAINBOW TROUT (N+S.E.M.) VARIABLE RESTING 0 min PB 15 min PB 1 hr PB 4 hr PB N La" (mM) 0.90 (±0.31) 4.29 (tO.30)* 5.55 (±0.37)* 8.40 (±0.69)* 5.29 (±0.55)* 10 H* (xl0"8M) 1.358 (±0.099) 2.705 (±0.131)* 2.324 (±0.148)* 1.958 (±0.111)* 1.258 (±0.074) 10 AD (xlO"9M) 1.2 (to.3) 36.6 (±12.5)* 24.2 (t8.1)* 13.8 (±3.4)* 5.5 (±1.3)* 8 NA (xlO"9M) 1.6 (tO.3) 26.7 (t6.4)* 24.0 (±11.1)* 16.5 (±6.6)* 9.8 (±3.4)* 8 DOPA (xlO'9M) o (to) o (to) 0 (±0) 0 (±0) 0 (±0) 8 pHe 7.841 (+0.038) 7.542 (±0.024)* 7.607 (±0.028)* 7.675 (±0.028)* 7.884 (±0.023)* 13 pHi 7.292 (±0.025) 7.283 (±0.019) 7.327 (±0.020) 7.360 (±0.018)* 7.400 (±0.023)* 13 Hct (%) 19.5 (±1.2) 27.7 (±1.4)* 25.4 (±1.6)* 24.6 (±1.6)* 20.6 (±2.2) 6 Hb (g7.) 5.72 (±0.35) 6.92 (±0.51)* 6.91 (±0.56) 6.47 (±0.28) 5.86 (to.47) 6 MCHC (9/100 ml) 0.30 (±0.01) 0.25 (±0.01)* 0.27 (±0.02) 0.27 (±0.02) 0.29 (to.01) 6 Ca02 (vole %) 8.1 (±0.6) 8.4 (±0.7) 8.6 (±0.8) 9.0 (±0.7)* 8.4 (±0.8) 6 C A0 2 ( m i 02/g Hb) 1.41 (tO.03) 1.21 (±0.03)* 1.24 (±0.05) 1.39 (to.07) 1.42 (to.06) 6 Pa02 (torr) 93.8 (t2.7) 68.3 (±3.2)* 92.9 (±6.2) 101.4 (t5.1)* 101.1 (±4.5) 6 Vf (min"1) 88.7 (t2.2) 39.0 (±1.4)* 94.0 (±1.5)* 89.0 (±2.1) 87.0 (±3.6) 3 Note: PB«Post-burst aerobic activity at 80% Ucrit ; Temperature: 5.0 - 15.0 °C •-Significantly different from RESTING (Student's t-Test; t_ q(.) DISCUSSION Severe p h y s i o l o g i c a l disturbances were observed tn freshwater rainbow trout during and following a period of burst swimming; f o r the aost part these were corrected within the f i r s t 4 hr of post-burst aerobic a c t i v i t y at 80% U c r i t . The r e l a t i o n s h i p between blood hydrogen ion (H+) concentration and l a c t a t e (La ) l e v e l s during and subsequent to a burst swim i s i l l u s -t rated i n F i g . l . It cannot be assumed that a l l of the increase i n H + de-pi c t e d here i s of metabolic o r i g i n ( i e . from l a c t i c acid d i s s o c i a t i o n ) . Other studies (eg. Wood et a l 1977, Turner et_ a l 1983 ) have suggested that t h i s type of H + data i s i n d i c a t i v e of nixed r e s p i r a t o r y and metabolic a c i d o s i s ( c f . Davenport 1974); these workers have calculated that at immed-i a t e end-burst the a c i d o s i s i s about 48% r e s p i r a t o r y and 52% metabolic but can become greater that 75% metabolic within 30 min of recovery (see Turner et a l 1983 ). The early peak of the r e s p i r a t o r y contribution has been a t t r i -buted to elevated a r t e r i a l C0^ tensions associated with high l e v e l s of 0^ metabolism early i n the a c t i v i t y period (Jones & Randall 1978) followed by d i r e c t metabolic acid t i t r a t i o n of plasma HC0~ (see McDonald jet a l 1982). Blood acid-base status i s s h i f t e d to predominately metabolic a c i d o s i s with continued muscle H + e f f l u x i n t o the c i r c u l a t i o n (Turner et_ a_l 1983 ). The f a c t that blood La" l e v e l s following the burst swim are s i g -n i f i c a n t l y elevated over pre-burst r e s t i n g l e v e l s i s an i n d i c a t o r of anaero-b i c metabolism during burst swims. F i g . l i n dicates that La l e v e l s do not peak i n the blood u n t i l at l e a s t 1 hr into recovery. Such delays i n muscle La" e f f l u x i n f i s h have been seen elsewhere (eg. Black et t l 1957 , Holeton et a l 1983, Turner et a l 1983) and i s i n contrast to mammalian sys-tems wherein peak blood La" l e v e l s are attained within a few minutes a f t e r 23 exhaustive exercise (eg. Margaria et a l 1963). A d d i t i o n a l La" production i s not responsible f o r t h i s delayed e f f l u x ; Black et a l (1962) found that La loads i n f i s h muscle c o n t i n u a l l y f a l l with recovery while Stevens and Black (1966) observed that they only increase again following addi-t i o n a l periods of burst exercise. Although plasma H + concentration peaks e a r l i e r than La", the t o t a l amount of La i n the blood during recovery exceeds the H + load. This discrepancy between both rate and degree of La" and H + muscle e f f l u x has been observed elsewhere (eg. P i i p e r et jal 1972, Holeton et a l 1983) and explained i n terms of ( i ) much of the muscle H + i s buffered i n t r a -c e l l u l a r ^ since trout muscle buffer capacity i s high (60 slykes; Cas-t e l l i n i & Somero 1981) and ( i i ) much of the plasma H + undergoes branchial e f f l u x to environmental water. The r e s u l t s of t h i s study also show that burst exercise followed by aerobic exercise i n freshwater rainbow trout causes increases i n plasma AD and NA; these Increases are associated with increases i n RBC volume, RBC pH, c i r c u l a t i n g Hb, and a r t e r i a l blood 0^ l e v e l s . Recent i n v e s t i g a t i o n s (Primmett 1982, Nikinmaa 1983) have shown that catecholamines a c t i v a t e H + e f f l u x from t e l e o s t RBC's i n v i t r o allow-ing erythrocyte pH regulation during e x t r a c e l l u l a r acidosis.. These studies have been substantiated by l a t e r observations (Heming 1984, Nikinmaa & HueBtis 1984) that AD stimulates net H + and HC0~ e f f l u x and net Na + and C l " i n f l u x across trout red c e l l membranes in v i t r o . Since Na + and C l are osmotically a c t i v e (while H + i s n o t ; Heming 1984), NaCl i n f l u x promotes c e l l u l a r H 20 uptake explaining the increase i n erythrocyte volume seen i n Fig.4. The AD-mediated net H + e f f l u x accounts f o r the increases i n RBC pH observed i n Fig.3. The r i s e i n RBC pH and volume i s expected to increase Hb-0_ a f f i n i t y and 0-CC v i a reverse Bohr and Root e f f e c t s and by 24 dilution of cellular organic phosphates, respectively (Weber & DeWilde 1975, Soivio & Niklnmaa 1981, Niklnmaa 1983). Therefore, the effectB of AD on RBC Ion transport w i l l provide the potential for Increased Mg and 0 2 transport ln trout. Fig.5 shows that CAC>2, PaOj, and V f are transiently decreased following exhaustive activity. It 1B assumed that the f a l l in C CL Is A 4-solely the result of the reduced PaCL.. Burst activity in f i s h i s associ-ated with decreases in ventilatory amplitude and frequency (for review see JohanBen 1971). It has been predicted that such changes result in a f a l l In g i l l water flow(GWF) and hence, g i l l water P_ (see Rahn 1966 for re-°2 view). Since Q Increases slightly with burst exercise (Neumann et a l 1983), this proposed f a l l in GWF would result ln a diffusion limitation for M Q (see Piiper 1982). It is known that changes in GWF are brought about by large changes in ventilation volume (Vg) and small changes in (eg. Cameron & Davis 1971). can easily be determined ln a free swimming animal but i s not the best indicator of V (Cameron & Davis 1971); even G B O , since both and PaC^ are decreased with burst activity in this study • may be signalling an overall f a l l ln GWF. If such is the case, then this f a l l ln GWF would explain the decrease in PaO_, and hence C 0_, seen 2 A *• in Fig.5. Pa0 2 and c A n 2 were restored to resting levels within 15 min of post-burst aerobic recovery (Fig.5) and this restoration was associated with a significant (but transient) overshoot above resting levels. This trend i s somewhat reversed by 1 hr of recovery in that i s restored to resting levels but Pa0 2 is significantly elevated above resting levels. It i s assumed that the I n i t i a l restoration of Pa0 2 and C A0 2 is the result • of the rapid rise and overshoot of V £ (ie. a sharp Increase In GWF); the Pa0 2 overshoot at 1 hr Into recovery is probably a function of AD-mediated 25 lamellar recruitment (see Randall 1982) and Increases in g i l l membrane permeability (Isaia et a l 1978). Fig. 5 shows that CaO^ is not decreased by burst exercise and is even significantly increased over resting levels by 1 hr of aerobic recov-ery. This is probably the result of (i) Increased Hb-02 a f f i n i t y due to predicted decreases in RBC organic phosphate levels (see above), ( i i ) a maintenance of RBC pH (Fig.3) which i s l i k e l y the result of AD-mediated RBC H + efflux (Nikinmaa 1983) and ( i i i ) significantly increased circulat-ing Hb levels (Fig.4). The increase In Ca02 i s not directly a function of the observed increase in Pa0 2 because the contribution of 0 2 tension was subtracted from values of 0 2 content (see METHODS AND MATERIALS). However, since aerobic exercise at 80% Ucrit i s associated with large increases in Q and decreases in Cv02 (Kiceniuk & Jones 1977, Randall & Daxboeck 1982), the elevations in Ca02 and PaO^ seen in Fig.5 w i l l translate into an over-a l l increase in blood 0^ transport to metabolizing tissues during post-burst aerobic activity. 26 CHAPTER II THE EFFECT OF ANAEROBIC EXERCISE FOLLOWED BY ADRENERGIC BLOCKADE IN RAINBOW TROUT 27 INTRODUCTION Burst activity in freshwater rainbow trout results from the re-cruitment of white muscle; i t s use necessitates anaerobic metabolism since this tissue i s poorly perfused and tissue 0^ demand exceeds blood 0^ deliv-major ery (Heisler 1980, 1982). The^metabolic endproducts of anaerobic glycolysis are La and H+. These ions diffuse from the muscle Into the extracellular space causing a plasma acid-base and ionic disturbance (see CHAPTER I ) . It has been predicted that this extracellular acidosis would produce a f a l l in RBC pH which, in turn, would impair blood 0^ loading at the g i l l via Bohr and Root effects and therefore restrict 0^ transport to the periphery during recovery from strenuous exercise (Randall 1970 ). The results of CHAPTER I show that 0^ transport is not inhibited by exercise-Induced extracellular acidosis in trout. The maintenance of CaO^ was associated with a maintenance of RBC pH and significant increases in plasma AD and NA levels. It was proposed in CHAPTER I that adrenergic reg-ulation of RBC pH allowed normal Hb-O^ carriage regardless of the plasma acidosis. The object of this study i s to examine the effects of propranolol infusion into rainbow trout a r t e r i a l blood Immediately following anaerobic exercise. Propranolol exhibits both competitive and noncompetitive inhib-ition of catecholamines for both alpha- and beta- receptors in f i s h (Wood 1975,1976; Wood & Shelton 1980). It i s the hypothesis of this investigation that post-exercise adrenergic blockade w i l l result in a f a l l in RBC pH due to inhibition of mechanisms responsible for erythrocyte H + efflux (Nikinmaa 1983). It i s expected that this predicted f a l l in RBC pH w i l l be associated with a decrease in Ca02 and 02CC because of a Root effect which should occur in a r t e r i a l blood during aerobic recovery. 28 METHODS AND MATERIALS Experimental animals Rainbow trout (Salmo galrdneri). of both sexes, were obtained from the Sun Valley Trout Farm (Mission, B.C.). These animals were sub-jected to physical conditioning (5.0 - 7.5 °C)and cannulation in the Identical manner outlined in Chapter I. The cannulated trout were allowed to recover for 18 hr in' a Brett (1964) respirometer/swim tube before any sampling procedures were employed. During this recovery period the fis h were swum at a resting aerobic level of activity (1.0 BL/sec). Experimental procedure Following 18 hr of recovery from surgical procedures, various blood variables were measured under 2 successive conditions of activity: (i) RESTING AEROBIC LEVEL (ie. the trout were swum at 1.0 BL/sec for 18 hr before the resting blood sample was taken) ( i i ) POST-BURST AEROBIC LEVEL (ie. following the resting level determination, the f i 6 h were (a) burst-swum to exhaustion (at a velocity which approximated the average burst-swim velocity observed ln Chapter I for animals of comparative size and physical conditioning) and immediately thereafter either (1) injected with 0.5 ml of -4 2 x 10 M propranolol (Niklnmaa 1984) In saline (Wolfe 1963) and 'chased' with a second injec-tion of 0.1 ml of saline (ie. 'Test' injection) or (2) injected with 0.5 ml of saline and then 29 'chased' with a second i n j e c t i o n of saline ( i e . 'sham' Injection) and then (b) swum at 1.0 BL/sec (a return to the aerobic r e s t i n g l e v e l during po6t-burst recovery) f o r 15 min a f t e r which time the post-burst aerobic blood sample was taken. Blood analysis At each sampling time, approximately 700 uL of whole blood was removed from the animal v i a the dorsal a o r t i c cannula. 50 uL of whole blood was e q u i l i b r a t e d with humidified room a i r (P of about 155 torr) i n °2 a tonometer thermostatted to the same temperature as the f i s h ; 20 uL of t h i s blood was then measured f o r a r t e r i a l blood 0^ carrying capacity (O^CC) with a Lex-0 2~Con oxygen content analyzer; 0 2CC was calculated as the d i f -ference between whole blood 0 2 content and plasma 0 2 content (see Wood et_ a l 1979) u t i l i z i n g values f o r plasma 0 2 s o l u b i l i t y extrapolated from data given by Altman and Dittmer (1971). The remaining whole blood was measured f o r pHe, RBC pH, C A0_, PaO- Hct, Hb, La", Ad, NA, MCHC i n the i d e n t i c a l 2 2 * (Sa0_) manner outlined i n CHAPTER I. A r t e r i a l blood Hb-0 2 saturation^was c a l c u l a -ted by d i v i d i n g values f o r C A n 2 by corresponding values f o r 0 2CC (see Packer 1979). Samples of water from the middle of the swim tube were removed with a syringe and inj e c t e d into a P n electrode and measurements of water P_ °2 2 (Pw02) were read from the associated Radiometer PHM-71 acid-base analzer. A l l data from the above procedures are given as arithmetic means T, 1 SE. The s i g n i f i c a n c e of changes i n v a r i a b l e magnitude between groups was determined using the Student's t-Test (t«0.95). 30 RESULTS The r e s u l t s of t h i s i n v e s t i g a t i o n are shown i n Table 2. Anaero-b i c exercise followed by a 'sham' i n j e c t i o n (EX) caused an Increase i n plasma La , a decrease i n pHe, an increase i n plasma AD, and a mainten-ance of RBC pH. Anaerobic exercise followed by propranolol i n j e c t i o n (EXP) produced s i m i l a r r e s u l t s to that seen i n EX except that there was a s i g -n i f i c a n t f a l l i n RBC pH (see Fig.6). There was no e f f e c t caused by EX or EXP on NA, Hct, Hb, MCHC, C ^ , 0 2CC, Sa0 2 > Pa0 2,and Pw02. 31 Figure 6. The e f f e c t of propranolol treatment following burst exercise on e x t r a c e l l u l a r and er y t h r o c y t i c pH; N«6 (+S.E.M.); ( * = s i g n i f i c a n t l y d i f f e r e n t from rest ). 32 F i g . 6 7.6 a 7 5 w u o w 7.4 • Propranolol O Control —J 1 I 1 L_ 7.8 7.9 8.0 8.1 8.2 WHOLE BLOOD pH TABLE 2. EFFECTS OF BURST EXERCISE FOLLOWED BY SHAM TNJECTION (EX) AND BURST EXERCISE FOLLOWED BY PROPRANOLOL INJECTION (EXP) IN RAINBOW TROUT (5.0 - 7.5 °C), VARIABLE REST,(N-12±SE) SIG: EX,(N-6tSE) 2 SIGT EXP.(N-6±SE) 3 SIGT La" (mM) 0.61 (±0.09) 0.05 5.32 (tO.40) NS 4.83 (±0.73) 0.05 AD (xlO~9M) 0.91 (±0.13) 0.05 5.82 (tl.44) NS 4.90 (±1.15) 0.05 NA (xlO"9M) 0.74 (±0.10) NS 0.50 (±0.06) NS 0.59 (±0.06) NS pHe 8.115 (to.024) 0.05 7.920 (to.045) NS 7.833 (±0.025) 0.05 RBC pH 7.491 (±0.015) NS 7.476 (tO.028) 0.05 7.418 (±0.011) 0.05 Hct (%) 21.3 (±1.1) NS 24.1 (±1.0) NS 21.3 (±2.1) NS Hb (g%) 6.57 (±0.33) NS 7.47 (±0.49) NS 5.96 (±0.35) NS MCHC (g%) 0.31 (±0.01) NS 0.31 (±0.01) NS 1.25 (±0.05) NS C A0 2 (mis 02/g Hb) 1.26 (±0.03) NS 1.23 (±0.06) NS 1.25 (±0.05) NS 02CC (mis 02/g Hb) 1.37 (±0.03) NS 1.28 (to.06) NS 1.40 (±0.08) NS Sa02 (%) 92 (±2) NS 96 (±2) NS 89 (±3) NS Pa02 (torr) 106.5 (±5.3) NS 115.0 (±4.1) NS 107.9 (±10.9) NS Pw02 (torr) 152.4 (tO.3) NS 151.9 (to.9) NS 153.8 (±1.1) NS Significance test between variables: Student's t-Test (t where SIG*-REST compared to EX ' SIG7-EX compared to EXP SIG.-REST compared to EXP Note: EX and EXP resting values are not s i g n i f i c a n t l y different (t q s ) ; these values are pooled above (N-12). 34 DISCUSSION Exhaustive exercise i n freshwater rainbow trout produces a meta-b o l i c a c i d o s i s i n a r t e r i a l blood as indicated by post-exercise increases in plasma La and decreases i n pHe (Table 2). The degree of change i n these v a r i a b l e s , r e l a t i v e to r e s t i n g l e v e l s , approximates that seen i n CHAPTER I (see F i g . l , 3 ; a t 15 min post-burst) suggesting that the burst exercise r e -gimes were quite s i m i l a r In the two studies. However, the adrenergic re-sponse to exercise in t h i s study was very d i f f e r e n t from that seen i n CHAPTER I. In the e a r l i e r study, both AD and NA showed large increases i n response to anaerobic a c t i v i t y but, in t h i s study, AD showed a smaller i n -crease while NA was unchanged. These differences i n catecholamine responses can be ascribed to seasonal v a r i a t i o n s in metabolic rate (Black et_ a l 1966, Szentivanyi e_t a l 1970, Hughes e£ a_l 1982) or reproductive condition (Wood 1976) because the experiments In CHAPTER I were done i n l a t e summer whereas those In t h i s CHAPTER were done i n early spring. The r e s u l t s of t h i s Investigation show that there i 6 only one s i g -n i f i c a n t d i f f e r e n c e between EX and EXP protocols. EX-treated f i s h maintained RBC pH r e l a t i v e to r e s t i n g conditions and EXP-treated f i s h exhibited a f a l l i n RBC pH (Fig.6). This i s d i r e c t evidence to support the hypothesis that adrenergic mechanisms (esp. beta) are responsible f o r erythrocyte pH regula-t i o n In t e l e o s t s during exercise-Induced plasma a c i d o s i s . Although EXP resulted i n a f a l l i n RBC pH, the predicted decrease in C 0_ and 0 oCC did not occur; the r e s u l t i n g e r y t h r o c y t i c a c i d o s i s did not A 2 2 cause a Root e f f e c t . This 16 probably due to secondary e f f e c t s of proprano-l o l on RBC membranes (eg. Szasz et a l 1977, Gardos et a l 1980). Certainly propranolol has a higher binding a f f i n i t y f o r adrenergic receptors (Ahlqvist 1948,1968) than either AD or NA (for review see Braun & Birnbaumer 1975) 35 but, propranolol also dramatically increases RBC Ca concentrations (RBC 2+ 2+ 2+ Ca levels are normally kept very low) by blocking (Ca - Mg )-ATPase which 2+ is necessary for active transport of Ca out of the cell (Schatzmann 1975). It is quite possible that the expected f a l l in C.0« and 0oCC (because of the A 2 2-2+ f a l l in RBC pH) was circumvented by Ca competition with Hb for organic phosphates within the erythrocyte (cf. Housten & Smeda 1979); such competi-tion would tend to negate both a Bohr (Nikinmaa 1983) and Root (Weber & DeWilde 1975) effect. It is evident from the results of this and the preceding CHAPTER that catecholamines are released into the general circulation of fish with exercise and that these hormones play a role in regulating erythrocytic pH in vivo during the activity-induced plasma acid-base disturbance. These findings suggest that earlier in vitro experiments (see Riggs 1970 for review), showing Root effects occuring in salmonid Hb's during extracellular acidosis, provide valuable information regarding the physical/chemical properties of the Hb's in isolation but do not often characterize such responses in conditions found in the intact animal. 36 REFERENCES Ahlquiet, R.P. (1948). A study of adrenotropic receptors. Am. J . P h y s i o l . 153; 586-600. Ahlquist, R.P. (1968). Agents which block adrenergic beta-receptors. Ann. Rev. Pharmacol. JJ: 259-272 Altman, P.C. & Dittmer, D.S. (1971). B i o l o g i c a l Handbook: Respiration and  C i r c u l a t i o n . Fed. Am. Soc. Exp. B i o l . , Bethesda, Md. pp.17-20. Ba r t e l s , H. & Bauumann, R. (1977). Respiratory function of haemoglobin. In: Respiration Physiology I I , vol.14, pp.107-117 (ed. J.G.Widelicombe). Univ. Park Press, Baltimore. Beamish, F.W.H. (1978). Swimming Capacity. In: F i s h Physiology, vol.VII, pp.101-187 (eds. W.S.Hoar & D.J.Randall). Academic Press , N.Y. Black, E.C. (1957). A l t e r a t i o n s i n the blood l e v e l of l a c t i c acid in cer-t a i n salmonid f i s h e s following muscular a c t i v i t y . I. Kamloops trout, Salmo  g a i r d n e r i . J . F i s h . Res. Bd. Can. 1^: 117-134. Black, E . C , Conner, A.R., Lam, K.C. & Chiu, W.G. (1962). Changes In glyco-gen, pyruvate and l a c t a t e i n rainbow trout (Salmo gairdneri) during and following muscular a c t i v i t y . J . F i s h . Res. Bd. Can. 19_: 409-436. Black, E . C , Tucker, H.H. & K i r k p a t r i c k , D. (1966). Oxygen d i s s o c i a t i o n curves of the blood of A t l a n t i c salmon (Salmo salar) acclimated to summer and winter temperatures. J . F i s h . Res. Bd. Can. 23(8): 1187-1194. Bone, Q., Kiceniuk, J . & Jones, D.R. (1978). On the r o l e of the d i f f e r e n t f i b e r types i n f i s h myotomes at intermediate swimming speeds. U.S. F i s h . W i l d l i f e Serv. F i s h . B u l l . 76: 691. Braun, T. & Birnbaumer, L. (1975). Hormone s e n s i t i v e adenyl cyclase systems: properties and f u n c t i o n . In: Comprehensive Biochemistry, vol.25,pp.»5-106(ed. M.Florkin & E.H.Stotz). E l s e v i e r . S c i . Publ. Co.,N.Y. Bre t t , J.R. (1964). The r e s p i r a t o r y metabolism of swimming performance of young sockeye salmon. J . F i s h . Res. Bd. Can. 2JL: 1183. B r e t t , J.R. (1972). The metabolic demand f o r oxygen i n f i s h , p a r t i c u l a r l y salmonids, and a comparison with other vertebrates. Resp. P h y s i o l . _1A^: 151. B r e t t , J.R., Hollands, H. & Alderdice, D.F. (1958). The e f f e c t of tempera-' ture on the c r u i s i n g speed of young sockeye and coho salmon. J . F i s h . Ras. Bd. Can. 15: 587-605. Davis, J.C. & Cameron, J.N. (1971). Water flow and gas exchange at the g i l l s of rainbow trout, Salmo g a i r d n e r i . J . exp. B i o l . ^4: 1-18. C a s t e l l i n i , M.A. & Somero, G.N. (1981). Buffering capacity of vertebrate muscle: c o r r e l a t i o n s with p o t e n t i a l s f o r anaerobic function. J . comp. P h y s i o l . 143: 191. 37 Davenport, H.W. (1974). The ABC of Acid-base Chemistry, 6th ed., Chicago: The University of Chicago Press. Dri e d z i c , W.R. & Hochachka, P.W. (1975). The unanswered question of high anaerobic c a p a b i l i t i e s of carp white muscle. Can. J. Zool. 53: 706. Fry, F.E.J. (1957). The aquatic r e s p i r a t i o n of f i s h . In: The Physiology of Fishes (ed. M.E.Brown), vol.1, pp.1-63. Academic Press, N.Y. Cardos, G., Szasz, I., Sarkadi, B. & Szebeni, J . (1980). Various pathways for passuve calcium transport i n red c e l l s . In: Membrane Transport In Eryth-rocytes , A. Benzon Symp.14 (eds. U.V.Lassen, H.H.Ussing & J.O.Wieth) pp.163-174, Munksgaard, Copenhagen. Gray, J . (1953). The locomotion of f i s h e s . Essays Mar. B i o l . pp.1-16. Gray, J . (1957). How f i s h e s swim. S c i . Am. .192: 48. Hammond, B.R. & Hickman, C P . J r . (1960). The e f f e c t of physi c a l condition-ing on the metabolism of l a c t a t e , phosphate, and glucose i n rainbow trout, Salmo g a i r d n e r i . J . F i s h . Res. Bd. Can. 22: 65. Heming, T.A. (1984). The r o l e of f i s h erythrocytes i n transport and excre-t i o n of carbon dioxide. Ph.D. Thesis, U n i v e r s i t y of B r i t i s h Columbia. H e i s l e r , N. (1980). Regulation of the acid-base 6tatus in f i s h e s . In: Environmental Physiology of Fishes, s e r i e s A, vol.35 (ed. M.A.Ali), Nato Advanced Study I n s t i t u t e s Series, Plenum Press, N.Y. B e i s l e r , N. (1982). T r a n s e p i t h e l i a l ion transfer processes as mechanisms fo r f i s h acid-base regulation l n hypercapnia and lactacldosi6. Can. J . Zool. 60: 1108-1123. Hochachka, P.W. (1961). The e f f e c t of ph y s i c a l t r a i n i n g on oxygen debt and glycogen reserves i n tro u t . Can. J . Zool. 39.: 767. Holeton, G.F. (1968). c i t e d by: Randall, D.J. (1970). Gas exchange in f i s h . ' In: F i s h Physiology-. VOL.IV (eds. W.S.Hoar & D.J.Randall) pp.253-292, Academic Press, N.Y. Holeton, G.F., Newmann, P. & H e i s l e r , N. (1983). Branchial ion exchange and acid-base regulation a f t e r strenuous exercise in rainbow trout (Salmo  g a i r d n e r i ) . Resp. P h y s i o l . 51_: 303. Houston, A.H. & Smeda, J.S. (1979). Thermoacclimatory changes in the ionic mlcroenvironment of hemoglobin i n the stenothermal rainbow trout and eury-thermal carp. J . exp. B i o l . B0: 317. Hughes, G.M., Peyraud, C , Peyraud-Waitzenegger, M. & S o u l i e r , P. (1982). P h y s i o l o g i c a l evidence for the occurence of pathways Bhunting blood away from the secondary lamellae of eel g i l l s . J . exp. B i o l . ^8: 277-288. 38 I s a i a , J . , Maetz, J . & Hayvood, G.P. (1978). E f f e c t s of epinephrine on branchial non-electrolyte permeability In rainbow t r o u t . J . exp. B i o l . 74: 227. Johansen, K. (1971). Comparative physiology: gas exchange and c i r c u l a t i o n i n f i s h e s . Ann. Rev. P h y s i o l . 33: 569-612. Jones, D.R. (1971). The e f f e c t s of hypoxia&nd anaemia on the swimming per-formance of rainbow trout (Salmo g a i r d n e r i ) . J . exp. B i o l . J55: 541. Jones, D.R. & Randall, D.J. (1978). The re s p i r a t o r y and c i r c u l a t o r y systems during exercise. In: F i s h Physiology, vol.VII (eds. W.S.Hoar & D.J.Randall) pp.425-501, Academic Press, N.Y. Kicenluk, J.W. (1975). Some aspects of exercise physiology i n f i s h . Ph. D. Thesis, University of B r i t i s h Columbia. Kicenluk, J.W. & Jones, D.R. (1977). The oxygen transport system i n trout (Salmo gairdneri) during sustained exercise. J . exp. B i o l . £9: 247. Krogh, A. (1941). The Comparative Physiology of Respiratory Mechanisms. Univ. of Pennsylvania Press, P h i l a d e l p h i a . Margaria, R., C e r r e t e l l i , P. dePrampero, P.E., Massari, C. & T o r r e l l i , G. (1963). K i n e t i c s and mechanisms of oxygen debt a f t e r muscle contraction in man. J . Appl. P h y s i o l . 1_9: 623. Mazeaud, M.M. & Mazeaud, F. (1981). Adrenergic responses to stress i n f i s h . In: Stress i n F i s h , (ed. A.D.Pickering), pp.49-55, Academic Press, N.Y. McDonald, D.C, Walker, R.L., Wilkes, P.R.H. & Wood, CM. (1982). H + excre-t i o n i n the marine te l e o s t parophys vetulus. J . exp. B i o l . _98_: 403. Nakatani, F.E. (1957). Changes i n the Inorganic phosphate and l a c t a t e l e v e l s i n the blood plasma and muscle t i s s u e of adult steelhead trout a f t e r stren-uous swimming. Univ. Wash., Sch. F i s h . Tech. Rep. JJO: 1-14. Neumann, P., Holeton, G.F. & H e i s l e r , N. (1983). Cardiac output and regional blood flow i n g i l l s and muscles a f t e r exhaustive exercise i n rainbow trout (Salmo g a i r d n e r i ) . J . exp. B i o l . 105: 1. Nikinmaa, M. (1982). Adrenergic regulation of haemoglobin oxygen a f f i n i t y i n rainbow trout red c e l l s . J . comp. P h y s i o l . 152: 67. Nikinmaa, M. (1983). E f f e c t s of adrenaline on red c e l l volume and concenta-t i o n gradient of protons across the red c e l l membrane i n the rainbow trout Salmo g a i r d n e r i . Molec. P h y s i o l . 2_: 287-297. Nikinmaa, M. £. Huestis, W.H. (1984). Adrenergic swelling of nucleated eryth-rocytes: c e l l u l a r mechanism In a b i r d , domestic goose, and two t e l e o s t s , s t r i p e d bass and rainbow t r o u t . J . comp. P h y s i o l , i n press. Packer, R.K. (1979). Acid-base balance and gas exchange i n brook trout (Salvelinus f o n t l n a l i s ) exposed to a c i d i c environments. J.exp. B i o l . 7_9: 127. 39 Perutz, M.F. & Brunori, M. (1982). Stereochemistry of cooperative e f f e c t s i n f i s h and amphibian haemoglobins. Nature 299; 421. P i i p e r , J . (1982). Respiratory gas exchange at lungs, g i l l s and t i s s u e s : mechanisms and adjustments. J . exp. B i o l . 100: 5-22. P i i p e r , J . , Meyer, M. & Drees, F. (1972). Hydrogen ion balance i n the e l a s -mobranch, Scyliorhynus s t e l l a r i s . a f t e r exhausting a c t i v i t y . Reap. Ph y s i o l . 16: 290. Powers, D.A. (1980). Molecular ecology of tel e o s t f i s h hemoglobins: Strate-gies f o r adapting to changing environments. Amer. Zool. 20: 139. Primmett, D.R.N. (1982). The r o l e of noradrenaline i n i n t r a c e l l u a r pH regulation i n rainbow trout (Salmo g a i r - n e r i ) . B.Sc. Thesis. U n i v e r s i t y of B r i t i s h Columbia. Rahn, H. (1966). Aquatic gas exchange: theory. Resp. P h y s i o l . 1^ : 1-12. Randall, D.J. (1970). Gas exchange i n f i s h . In: F i s h Physiology, vol.IV (eds. W.S.Hoar & D.J.Randall) pp.253-292, Academic Press, N.Y. Randall, D.J. (1982). The con t r o l of r e s p i r a t i o n and c i r c u l a t i o n i n f i s h during exercise and hypoxia. J . exp. B i o l . 100: 275-288. Randall, D.J. & Daxboeck, C. (1982). Cardiovascular changes i n rainbow trout (Salmo g a i r d n e r i Richardson) during exercise. Can. J . Zool. 60: 1135-1140. Riggs, A. (1970). Properties of f i s h hemoglobins. In: F i s h Physiology, v o l . IV (eds. W.S.Hoar & D.J.Randall) pp.209-252, Academic Press, N.Y. Ruud, J.T. (1954). Vertebrates without erythrocytes and blood pigment. Nature 173: 848-850. Schatzmann, H.J. (1975). Active calcium transport and Ca -activated ATPase i n human red c e l l s . In: Current Topics i n Membranes and Transport, vol.6 (eds. F.Bronner & A . K l e i n z e l l e r ) pp. 125-168, Academic Press, N.Y. Smith, L.S. & B e l l , G.R. (1964). A technique f o r prolonged blood sampling in free-swimming salmon. J . F i s h . Res. Bd. Can. 21_: 1775. Soi v i o , A. & Nikinmaa, M. (1981). The swelling of erythrocytes i n r e l a t i o n to the oxygen a f f i n i t y of the blood of the rainbow trout, Salmo gairdneri Richardson. In: Stress and F i s h , (ed. A.D.Pickering), pp.103-119, Academic Press, N.Y. Stevens, E.D. & Black, E.C. (1966). The e f f e c t of intermittent exercise on carbohydrate metabolism i n rainbow trout (Salmo g a i r d n e r i ) . J . F i s h . Res. Bd. Can. 23: 471. Szasz, I., Sarkad^., B. & Gardos, G. (1977). Mechanism of calcium dependant s e l e c t i v e rapid K -transport induced by propranolol i n red c e l l s . J . Membr. B i o l . 35: 75-93. AO Szentivanyi, M., Kunos, C. & Juhasz-nagy, A. (1970). Modulator theory of adrenergic receptor mechanism: vessels of the dog hindlimb. AM. J. Physiol. 218(3): 869-875. Turner, D.T., Wood, CM. & Clark, D. (1983). Lactate and proton dynamics ln the rainbow trout (Salmo gairdneri). J. exp. Bi o l . 104: 2A7. Wardle, CS. (1978). Non-release of lac t i c acid from anaerobic swimming muscle of plaice, Pleuronectes platessa : a stress reaction. J. exp. Bio l . 77: 141. Weber, R.E. & DeWilde, A.M. (1975). Oxygenation properties of hemoglobins from f l a t f i s h , plaice and flounder. J. comp. Physiol. 101: 99. Wolfe, K. (1963). Physiological salines for freshwater teleosts. Progr. f i s h Cult. 25: 135. Wood, CM. (1975). A c r i t i c a l examination of the physical and adrenergic factors affecting blood flow through g i l l s of the rainbow trout. J. exp. Bi o l . 60: 241-265. Wood, CM. (1976). Pharmacological properties of the adrenergic receptors regulating systemic vascular resistance in the rainbow trout. J. comp. Physiol. _107: 211-228. Wood, CM., McMahon, B.R. & McDonald, D.G. (1977). An analysis of changes In blood pH following exhaustive activity in the starry flounder, Platichthys stellatus. J. exp. Bi o l . J>9: 173-185. Wood, CM., McMahon, B.R. & McDonald, D.G. (1979). Respiratory gas exchange in the resting starry flounder, Platichthys stellatus: A comparison with other teleosts. J. exp. Biol. J_8: 167-179. Wood, CM. & Shelton, G. (1980). Cardiovascular dynamics and adrenergic responses of the rainbow trout in vivo. J.exp. Bi o l . B7_: 247. Woodward, J.J. (1982). Plasma catecholamines in resting trout, Salmo  gairdneri Richardson, by high pressure liquid chromatography. J. Fish Biol. 21.: 429-432. Zeidler, R. & kirn, H.D. (1977). Preferential hemolysis of postnatal calf red cells induced by internal alkalinization. J. Gen. Physiol. 70= 385-401. Zettner, A. & Mensch, A.H. (1967). The use of atomic absorption spectroscopy in hemoglobinometry. Amer. J. Clin. Pathol. 48: 225-241. o 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
https://iiif.library.ubc.ca/presentation/dsp.831.1-0096135/manifest

Comment

Related Items