Influence of enalapril on established pressure-overload cardiac hypertrophy in low and normal renin states in female rats.
To determine whether effects of angiotensin converting enzyme (ACE) inhibitors on well-established pressure overload-induced cardiac hypertrophy and coronary remodeling depend upon normal plasma renin levels, the influence of enalapril on ventricular mass and coronary vascular resistance (CVR) was determined in a low-renin female rat model of chronic pressure overload, (deoxycorticosterone acetate hypertension, DOCA), and compared to its effect in a normal-renin model, (aortic construction, AC). Six weeks after experiment initiation, plasma renin activity of DOCA-treated rats was reduced to approximately 12% that of sham-treated and AC-treated groups. Enalapril was then added to the drinking water of half the animals in each group for two additional weeks. Comparing experimental groups to controls, this delayed enalapril treatment had 1) no effect on the elevated arterial pressures, 2) no effect on the elevated coronary resistance, and, in the DOCA group, 3) no effect on cardiac hypertrophy. However, this brief enalapril treatment reduced absolute and relative ventricular weights of AC rats. These data suggest that circulating renin is required for the anti-hypertrophic efficacy of late-onset brief treatment with enalapril. Since enalapril-induced reversal of cardiac hypertrophy in AC rats was not accompanied by reversal of coronary remodeling, growth signals other than angiotensin II may be involved in coronary remodeling.
Heller
L J
LJ
Department of Medical and Molecular Physiology, University of Minnesota, Duluth, School of Medicine, Duluth, MN 55812, USA. lheller@d.umn.edu
Katz
S A
SA
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D006332:Cardiomegaly / Q000188:drug therapy* / Q000209:etiology; D003326:Coronary Circulation / Q000187:drug effects; D003900:Desoxycorticosterone; D004656:Enalapril / Q000627:therapeutic use*; D005260:Female; D006973:Hypertension / Q000139:chemically induced / Q000150:complications*; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D012083:Renin / Q000502:physiology*; D014655:Vascular Resistance / Q000187:drug effects
D000806:Angiotensin-Converting Enzyme Inhibitors; D003900:Desoxycorticosterone; D004656:Enalapril; D012083:Renin