INHIBITION OF THE PRESSOR ACTION OF ANGIOTENSIN BY VASOPRESSIN IN NEPHRECTOMIZED RATS (ADH, ANTIDIURETIC HORMONE).
Item
-
Title
-
INHIBITION OF THE PRESSOR ACTION OF ANGIOTENSIN BY VASOPRESSIN IN NEPHRECTOMIZED RATS (ADH, ANTIDIURETIC HORMONE).
-
Identifier
-
AAI8423053
-
identifier
-
8423053
-
Creator
-
BARRY, CATHERINE ROSE.
-
Contributor
-
Lawrence R. Krakoff
-
Date
-
1984
-
Language
-
English
-
Publisher
-
City University of New York.
-
Subject
-
Biology, Animal Physiology
-
Abstract
-
The effects of endogenous and exogenous vasopressin on the pressor dose-response curve to angiotensin II were studied in unanesthetized nephrectomized rats. Subpressor infusions of vasopressin (0.2-0.4 mU/kg/min) diminished sensitivity to angiotensin II in the presence or absence of ganglionic blockade (pentolinium, 10 mg/kg iv). This was indicated by the parallel rightward shift in the dose-response curve which was completely reversed in ganglionic blocked animals by administration of the pressor antagonist of vasopressin, dPMeTyrAVP (50 ug/kg). When dPMeTyrAVP was administered without prior infusion of vasopressin, a non-parallel enhancement of angiotensin II was seen in nephrectomized rats before, but not after, ganglionic blockade. These effects of vasopressin and dPMeTyrAVP appear to be specific for angiontensin II since dose-response curves to norepinephrine were not modified in a manner similar to those of angiotensin when studied under identical conditions.;In addition to its effect on pressor responses to angiotensin, dPMeTyrAVP causes a depressor response ((DELTA) mean arterial pressure, -13 mmHg) in our animals. This was found to be due, at least in part, to higher levels of endogenous vasopressin in nephrectomized rats (10.0 pg/ml) as compared to sham-operated controls (3.6 pg/ml).;Our results demonstrate an inhibitory effect of both endogenous and exogenous vasopressin on the pressor response to angiotensin II. They also indicate that this effect is specific since norepinephrine is not affected in a similar manner. In addition, the ability of ganglionic blockade to abolish the non-parallel enhancement of angiotensin II by dPMeTyrAVP, but not the parallel inhibition of vasopressin infusion, indicates that both neurally-mediated and direct vasular inhibitory mechanisms exist.
-
Type
-
dissertation
-
Source
-
PQT Legacy CUNY.xlsx
-
degree
-
Ph.D.
-
Program
-
Biomedical Sciences
