Changes of angiotensin converting enzyme (ACE) levels during activation of the renin-angiotensin-aldosterone system (RAAs).

The aim of this study was to evaluate the changes of ACE levels during RAAs activation induced by: 1) a continuous graded bicycle ergometer test performed in a group of 15 males health youths aged between 21 and 30 years, with average age of 25.8 +/- 2.85 years; 2) i.m. injection of 20 mg of frusemide in 11 health youths (10 males and 1 female), aged between 20 and 30 years, with average age of 24.09 +/- 2.77 years; 3) dialytic treatment in 25 patients (12 males and 13 females), suffering from chronic renal failure, aged between 26 and 68 years, with average age of 54 +/- 15.42 years. Plasmatic renin activity (PRA), aldosterone (ALD) and ACE levels were determined by RIA in basal conditions and at peak of exercise in group 1, 15 minutes after i.m. injection of frusemide in group 2 and after a session of dialysis in group 3. In all the experimental conditions studied there was an activation of the renin-angiotensin system with significant increase of the PRA, ALD and ACE levels.