Renal vasodilatation after inhibition of renin or converting enzyme in marmoset.
The relative importance of angiotensin II for the renal vasodilatory response after converting-enzyme inhibition was evaluated by a comparison of the effects of converting-enzyme and renin inhibition on renal vascular resistance. Renal, mesenteric, and hindquarter blood flows were measured with chronically implanted ultrasonic-pulsed Doppler flow probes in conscious, mildly volume-depleted marmosets after administration of a converting-enzyme inhibitor (enalaprilat, 2 mg/kg iv), a synthetic renin inhibitor (CGP 29,287, 1 mg/kg iv), or a renin-inhibitory monoclonal antibody (R-3-36-16, 0.1 mg/kg iv). Enalaprilat reduced blood pressure (-16 +/- 4 mmHg, n = 6) and induced a selective increase in renal blood flow (27 +/- 8%, n = 6). CGP 29,287 and R-3-36-16 induced comparable reductions in blood pressure (-16 +/- 4 mmHg, n = 6 and -20 +/- 4 mmHg, n = 5, respectively) and selective increases in renal blood flow (36 +/- 12%, n = 6 and 34 +/- 16%, n = 4, respectively). The decrease in renal vascular resistance was of similar magnitude for all of the inhibitors (enalaprilat -28 +/- 3%, CGP 29,287 -32 +/- 6%; and R-3-36-16 -33 +/- 7%). These results indicate that the renal vasodilatation induced after converting-enzyme or renin inhibition is mainly due to decreased formation of angiotensin II.
D000806:Angiotensin-Converting Enzyme Inhibitors; D000818:Animals; D002143:Callitrichinae / Q000502:physiology*; D004656:Enalapril / Q000031:analogs & derivatives / Q000494:pharmacology; D015773:Enalaprilat; D005260:Female; D008297:Male; D009842:Oligopeptides; D012079:Renal Circulation; D012083:Renin / Q000494:pharmacology; D014655:Vascular Resistance / Q000187:drug effects; D014664:Vasodilation; D000092502:Renin Inhibitors
D000806:Angiotensin-Converting Enzyme Inhibitors; D004656:Enalapril; D015773:Enalaprilat; D009842:Oligopeptides; D012083:Renin; D000092502:Renin Inhibitors; C045501:CGP 29287