AJP - Endocrinology and Metabolism, Vol 245, Issue 4 410-E416, Copyright © 1983 by American Physiological Society
Effects of verapamil on renin and aldosterone in the dog and rat
M. W. Roy, G. P. Guthrie Jr, F. P. Holladay and T. A. Kotchen
The purpose of this study was to evaluate the effects of calcium channel
blockade on renin secretion and plasma aldosterone. Verapamil infusion
(0.004 mg X kg-1 X min-1) into the renal artery of uninephrectomized dogs
with an intact kidney resulted in significant increases (P less than 0.05)
in renal blood flow, creatinine clearance, and the excreted fractions of
Na+ and Cl-; renin secretion decreased (P less than 0.05) and plasma
aldosterone did not change. Conversely, renal arterial infusion of
verapamil in dogs with nonfiltering, denervated, papaverine-treated kidneys
resulted in no change in renal blood flow and a significant increase (P
less than 0.05) in renin secretion. In the rat, compared with untreated
control animals, dietary verapamil (12.5 mg X kg-1 X day-1) did not effect
plasma renin activity but significantly suppressed plasma aldosterone (P
less than 0.001) in animals on NaCl-restricted [14.7 +/- 5.4 vs. 41.6 +/-
7.8 ng/dl (SE)] and NaCl-free [103.7 +/- 7.5 vs. 156.7 +/- 18.7 ng/dl (SE)]
diets. In addition, verapamil suppressed (P less than 0.0003) plasma
corticosterone [16.1 +/- 5.4 vs. 52.8 +/- 7.1 microgram/dl (SE)]. Thus,
acute but not chronic verapamil administration stimulates renin release in
the nonfiltering kidney, and chronic verapamil inhibits adrenal
mineralocorticoid and glucocorticoid secretion. The disparate effects of
verapamil on renin secretion from intact and nonfiltering kidneys may be
due to actions of the Ca2+ channel blocker on renal hemodynamic and/or
renal tubular mechanisms in the intact kidney that mask a direct effect of
verapamil on renin-secreting cells.
