Influence of angiotensin II and mannitol on local renal blood flow

Abstract

The present report outlines investigations in experimental animals (dogs) conducted for the purpose of studying the effect of angiotensin II and 10 ~ mannitol solution on local renal blood flow. Most of the experiments were carried out in normovolaemic conditions, a few of them in haemorrhagic shock. Following the description of the experimental set-up and the procedure employed, the response of the arterial blood pressure and the local renal blood flow to mannitol infusion in normovolaemia is delineated with the help of a tabular summary. Experiments in haemorrhagic shock seem to suggest that concurrent intravenous administration of mannitol and angiotensin II in acute hypotensive circulation is warranted if preceding volume replacements have not yielded an adequate stabilizing effect on the circulation.Clearance studies on experimental animals have revealed that the angiotensin-induced depressor effect on renal function is prevented by simultaneous mannitol administration. Human clearance experiments have shown that on the other hand renal function following sole administration of angiotensin II is compensated in part by co-administering mannitol.The observation that clearance studies, due to their low resolving power, are apt to illuminate only relatively protracted functions prompted us to investigate the acute changes in local renal blood flow and blood pressure after administration of angiotensin II and mannitol using a suitable Hensel probe. MethodExperiments were conducted on 17 fasted mongrel dogs of both sexes in the supine position. Their weight varied from 15 to 38 kg.