Converting enzime inhibition and renal function of conscious uninephrectomized rats

We studied the effect of a Converting Enzyme Inhibitor, Captopril, on renal function of conscious, chronically instrumented uninephrectomized rats three weeks after surgery and normal two kidney rats. Captopril increased glomerular filtration rate from 9.28 n 0.50 to 14.23 n 1.07 ml/min.kg and effective renal plasma flow from 31.6 n 2.4 to 45.8 n 3.7 ml/min.kg in two kidney rats. Glomerular filtration rate and effective renal plasma flow of uninephrectomized rats did not change after acute converting enzyme inhibition (from 6.96 n 0.61 to 7.16 n 0.39 and 24.5 n 2.2 to 27.9 n 1.5 ml/min.kg respectively). Plasma renin activity was lower in uninephrectomized rats (0.72 n 0.15ng AngI/ ml.h) than in intact rats (1.41 n 0.20 ng AngI/ml.h). Acute converting enzyme inhibition increased urinary sodium excretion, fractional sodium excretion and plasma renin activity in both, two kidney and uninephrectomized rats without changes of mean arterial pressure. Present data suggest that the Angiotensin II does not participate in the control of glomerular filtration rate and effective renal plasma flow of uninephrectomized rats but it is implicated in the control of Na homeostasis.