抄録
Recently there is considerable evidence to support the hypothesis that renin-angiotensin system play an important role of homeostasis in the body fluid. The author followed plasma renin activity in 12 patients with acute renal failure. Plasma and renal renin activity were measured in experimental animals, and juxtaglomerular cells and granules were observed histologically. Plasma renin activity obtained in 6 patients were significantly increased in oliguric phase. The incidence of increased plasma renin activity was greater among patients with shock and bleeding. In one patient extremely low plasma renin activity was found during the oliguric phase. In this case pathologically the profound damage of renal parenchyma was demonstrated. Experimentally in all kinds of acute renal failure plasma renin activity decreased as the renal damage proceed. These data seem to support the diagnosis of advanced damage of renal parenchyma in patient who showed constantly low plasma renin activity during the oliguric phase. Toxic acute renal failure is frequently accompanied by shock or bleeding, so it can not be clearly distinguished from ischemic acute renal failure. In case of mercurial intoxication plasma renin activity was high during the oliguric phase. In this case the increase of plasma renin activity was seemed to be induced by accompaning gastrointestinal bleeding, and the kidney was still able to secrete renin in response to bleeding. As the matter of fact, according to two cases with constant high plasma renin activity during the oliguric phase, the causes of death were thought to be extrarenal factors; heart failure and massive gastrointestinal bleeding respectively. Pathologically the destruction of renal parenchyma were not so prodound, and there might be reversible factors so far as renal function is concerned. It is concluded that renin in acute renal failure is secreted as the result of disturbed homeostasis among renin releasing factors and function of juxtaglomerular cells. The observation of the changes of plasma renin activity is very useful to analyse homeostasis of the body fluid and renal lesion in acute renal failure.
