A method for determination of renin activity in dog's plasma and renal tissue

Abstract

A procedure based on that of Boucher et al. (Can. J. Physiol. Pharmacol. 45, 881 (1967)) for the microdetermination of plasma renin activity in the rat is described for the measurement of the same parameter in 1 ml of dog plasma. This procedure permits serial determinations and uses homologous substrate with incubation with Dowex 50W-X2 (NH₄⁺) at pH 5.5 for 12 h. The results are expressed as nanograms of angiotensin formed per milliliter of plasma after 12 h of incubation. The mean plasma renin activity in healthy dogs was 1.04 ng/ml per h, ± 1.03 S.D., with a range of 0–3.3 ng. This procedure was applied to the measurement of renin activity in renal tissue.