Acute hemodynamic effects of the active metabolite of imidapril, (4S)-3-((2S)-2-[N-((1S)-1-carboxy-3-phenyl-propyl)amino]propionyl)-1- methyl-2-oxoimidazolidine-4-carboxylic acid, and enalaprilat in anesthetized dogs.

The hemodynamic effects of imidapril, a novel nonsulfhydryl angiotensin-converting enzyme inhibitor, were examined in anesthetized dogs by the intravenous injection of its active metabolite 6366A ((4S)-3-((2S)-2-[N-((1S)-1-carboxy-3- phenylpropyl)amino]propionyl)-1-methyl-2-oxoimidazolidine-4-carboxylic acid, CAS 89371-44-8) and were compared to those of enalaprilat. 6366A (1-100 micrograms/kg) reduced the blood pressure and total peripheral resistance in a dose-dependent manner, while causing no marked changes in heart rate, LV dp/dtmax, and pulmonary arterial pressure. The cardiac output and stroke volume were slightly increased. Blood flow in the common carotid artery, the vertebral artery, and the femoral artery was reduced or tended to decrease, while the superior mesenteric arterial blood flow was increased. These effects were similar to those of enalaprilat. 6366A did not inhibit the pressor response of angiotensin II, but markedly inhibited that of angiotensin I, and the effects of 6366A on regional blood flow were opposite to those of angiotensin II. Thus, 6366A appears to produce its hemodynamic effects by angiotensin converting enzyme inhibition, as does enalaprilat. 6366A also tended to decrease myocardial oxygen consumption. These results suggested that the hemodynamic effects of imidapril on the heart and on regional blood flow are similar to those of enalapril.