Activity of the renin-angiotensin-aldosterone (RAA) and secretion of the atrial natriuretic peptide (ANP) in patients with chronic renal failure.

In 12 patients with chronic renal failure (CRF) treated with haemodialyses and in 21 healthy controls plasma renin activity (PRA) and the concentrations of aldosterone and atrial natriuretic peptide (ANP) were determined in serum before and after blockade of the angiotensin converting enzyme with captopril. The study was carried out under conditions of the so called bed rest test (BR) and water immersion test (WI). After captopril administration a significant rise of PRA was noted in both groups with a drop of aldosterone level which was significant only in the control group. Captopril administration had no effect on serum ANP level. The results of the study are not suggesting the presence of a close relationship between ANP secretion and the activity of the RAA system in healthy controls and in CRF patients.