AJP - Endocrinology and Metabolism, Vol 260, Issue 2 E269-E271, Copyright © 1991 by American Physiological Society
Effect of a new mineralocorticoid antagonist mespirenone on aldosterone-induced hypertension
J. Opoku, M. Kalimi, M. Agarwal and D. Qureshi
Department of Physiology, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298.
The effects of the mineralocorticoid antagonist mespirenone on the
development and maintenance of aldosterone-induced hypertension in
Sprague-Dawley rats has been studied. Uninephrectomized saline-drinking
male Sprague-Dawley rats were injected with either 0.2 ml olive oil, 50 g
aldosterone, 1 mg mespirenone, 50 g aldosterone plus 500 g mespirenone, or
50 g aldosterone plus 1 mg mespirenone, each dissolved in 0.2 ml olive oil.
Administration of aldosterone alone significantly increased the systolic
blood pressure (SBP) from a control value of 114 +/- 3.6 to 162 +/- 4 mmHg
by the end of the 3-wk experimental period. Mespirenone given alone had no
effect on SBP. However, mespirenone given in combination with aldosterone
reversed the hypertension caused by aldosterone in a dose-dependent manner.
Saline consumption and urinary output were slightly increased in
aldosterone-treated rats compared with the other groups, but the body and
organ weights were comparable in all groups. Microscopic examination of
kidney and heart showed no abnormalities due to mespirenone. These results
suggest that in vivo administration of mespirenone to Sprague-Dawley rats
effectively prevents the aldosterone-induced hypertension.
