Action du clopamide et de l'acide ethacrynique sur la sécrétion de rénine chez le chien.

Renin secretion was studied in anesthetized dogs (Pentobarbital), after an injection of 5 mg/kg i.v. clopamide (10 animals) or ethacrynic acid (10 animals). Renin activity in venous renal blood (Boucher's method), renal blood flow (electromagnetic flowmeter), blood pressure, diuresis and natriuresis have been measured simultaneously. Basic renin secretion was 22,4±8,2 ng/g of kidney/min. During the 8 min following the ethacrynic acid injection renin secretion increased to 74,4±41,1 ng/g of kidney/min ( p<0.005). Within the same time it dropped to 11.1±6.8 ng/g of kidney/min ( p<0.005) after clopamide. These variations of renin secretion are related to the diuretic's action on the nephron, and depend on an endorenal mechanism. Ethacrynic acid suppresses the corticopapillary gradient while clopamide does not. We have not found any correlation between renin secretion and either natriuresis (mg/min) or diuresis (ml/min). But there is a connection ( r=0.7367) between renin secretion after ethacrynic acid injection and sodium concentration in urine. [ABSTRACT FROM AUTHOR]