AJP - Heart and Circulatory Physiology, Vol 244, Issue 1 97-101, Copyright © 1983 by American Physiological Society
Regression of myocardial hypertrophy and influence of adrenergic system
S. Sen and R. C. Tarazi
Studies of regression of myocardial hypertrophy in spontaneously
hypertensive rats (SHR) suggest that the adrenergic system may play an
important role in the reversal of hypertrophy. The effect of propranolol on
reversal of hypertrophy, however, is still controversial. This study
describes the effect of propranolol, given alone or in combination with
hydralazine in different ratios for 4 wk, on blood pressure (BP),
ventricular weight, and myocardial catecholamine (MC) concentrations. The
data show that a certain ratio of propranolol to hydralazine (750:30) leads
to moderate BP control (196-156 mmHg) without increased MC (634 vs. 552
ng/g) and moderately reduced hypertrophy. Reduction of BP alone with
increased MC (hydralazine alone) or reduction of MC without BP control
(propranolol alone) failed to reduce hypertrophy. A significant correlation
between both ventricular weight and heart rate with MC (r = 0.6) was
obtained by multiple regression analysis. This study suggests that
adrenergic factors seem to play an important role in modulating structural
cardiac response to variations in arterial pressure.
