A study on three models of hypertension : genetic, mineralocorticoid, and ethanol-induced
department or school: Medicine, Faculty of
department or school: Anesthesiology, Pharmacology and Therapeutics, Department of
data provider: DSpace
degree campus: UBCV
creator: Chan, Thomas C. K.
issued: 2010-05-02T22:11:18Z
issued: 1982
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: The Okamoto-Aoki strain of spontaneously hypertensive rats (SHR) is probably the most studied animal model of hypertension. Previous experience from our laboratory indicated that the vascular smooth muscle of the SHR is hyper-reactive to pressor agents in vitro, and that the sensitivity to calcium is also altered in these tissues. Since there is evidence for sodium ion and sodium pump abnormalities in erythrocytes of hypertensive patients and animals, the decision was made to use the erythrocyte membrane as a model for studying calcium-membrane interactions in the SHR. The Ca⁺⁺/Mg⁺⁺ ATPase activities (both high and low affinity) in the erythrocyte membrane from SHR were measured and found to be significantly elevated when compared to those of normotensive controls (WKY). Other erythrocyte membrane enzymes are not different between the two groups. Passive calcium influx into intact erythrocytes at 4°C was examined using ⁴⁵Ca as tracer and a significant increase in the passive permeability to calcium across the SHRs erythrocyte membrane was found when compared to the WKYs. Other abnormalities in the SHR erythrocyte include a reduction in osmotic fragility and increased levels of membrane cholesterol, phosphatidyl choline and sphingomyelin with marginal decreases in phosphatidyl ethanolamine and phosphatidyl serine. These findings indicate that structural and compositional alterations are present in the SHR erythrocyte membrane and these may be related to the increased passive permeability to calcium and the possibly compensatory increase in Ca⁺⁺/Mg⁺⁺ ATPase activity described earlier. Studies on the erythrocyte membranes of DOCA/salt hypertensive (DOCA) rats revealed no major differences in the activities of the membrane enzymes between the DOCA and nephrectomized controls (NC) animals. Furthermore, no difference was observed in passive calcium permeability between the erythrocytes from both groups of animals. Contrary to what was found in the SHR, osmotic fragility o…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/24276
note: A STUDY ON THREE MODELS OF HYPERTENSION: " GENETIC, MINERALOCORTICOID, AND ETHANOL-INDUCED by THOMAS C. K. CHAN B . S c , The U n i v e r s i t y o f B r i t i s h C o l u m b i a , 1977 A T H E S I S SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY i n THE FACULTY OF GRADUATE STUDIES ( D e p a r t m e n t o f P h a r m a c o l o g y , F a c u l t y o f M e d i c i n e ) We a c c e p t t h i s t h e s i s as c o n f o r m i n g t o t h e r e q u i r e d s t a n d a r d THE UNIVERSITY OF BRITISH COLUMBIA O c t o b e r 1982 0 Thomas C. K. C h a n , 1982 In p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t of the requirements f o r an advanced degree at the U n i v e r s i t y o f B r i t i s h Columbia, I agree t h a t the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and study. I f u r t h e r agree t h a t p e r m i s s i o n f o r e x t e n s i v e copying of t h i s t h e s i s f o r s c h o l a r l y purposes may be granted by the head o f my department or by h i s or her r e p r e s e n t a t i v e s . I t i s understood t h a t copying or p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l not be allowed without my w r i t t e n p e r m i s s i o n . Department o f Pharmacology, Faculty of Medicine The U n i v e r s i t y o f B r i t i s h Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3 Date March 16, 1983 )E-6 (3/81) ( i i ) ABSTRACT The Okamoto-Aoki s t ra in of spontaneously hypertensive rats (SHR) i s probably the most studied animal model of hypertension. Previous experience from our laboratory indicated that the vascular smooth muscle of the SHR i s hyper-reactive to pressor agents in v i t r o , and that the s e n s i t i v i t y to calcium i s also altered in these t i ssues. Since there is evidence for sodium ion and sodium pump abnormalities in erythrocytes of hypertensive patients and animals, the decisi…
has type: Thesis/Dissertation
date issued: 1983-05
is shown at: 10.14288/1.0448020
language: eng
degree discipline: Pharmacology
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/24276