An investigation of the prolonged pressor response to renin in the nephrectomized rat.

1. In an investigation of the prolonged pressor response to renin that develops after nephrectomy, angiotensin I dose-response curves and rat renin clearances were studied in nephrectomized rats and paired sham-nephrectomized control animals under pentobarbitone anaesthesia. 2. Both threshold and slope of the angiotensin I dose-response curves were decreased at 15-27 h after nephrectomy. 3. The ratio of renin clearance (determined during renin infusions) in the nephrectomized rat to that in the paired sham-nephrectomized control animals was 0-49+/-0-03 (SEM), P less than 0-001 (n = 12 pairs). 4. Both factors contribute towards the prolongation of the blood pressure increase after intravenously administered renin in the nephrectomized animal.