[Comparisons of effects of Hoe-498 and enalapril in isolated guinea pig hearts and rat myocardium].
In isolated guinea pig hearts Hoe-498 (1 mg/kg ig) attenuated the cardiac effects of angiotensin I (ANG I) but not angiotensin II(ANG II), and potentiated those of brady-kinin(BK). Enalapril (MK-421) was without effect at this dose, but 30 mg/kg produced similar effects. In rat myocardium, the converting enzyme (CE) activities after Hoe-498 (1 mg/kg ig) pretreatment (15 min,1&6 h) were inhibited by 62.70 and 19%, repectively. Enalapril (30 mg/kg ig) pretreatment yielded similar inhibitions(74,76 and 50%,respectively). The results indicate that Hoe-498 is 30 times more potent as a CE inhibitor(CEI) than enalapril.