Abstract
The effect of captopril (SQ 14, 225) on the renal hemodynamics, cortical plasma flow (CPF) and noncortical plasma flow (NCPF), was studied in sodium-replete anesthetized dogs during aprotinin infusion. Mean blood pressure (MBP) increased by aprotinin (p < 0.05) and decreased by captopril (p < 0.02). Renal vascular resistance (RVR) tended to increase by aprotinin and decreased from 1.29 to 0.86 mm Hg/ml/h (74.7%) by captopril (p < 0.05). Renal vein renin activity (RRA) inclined to decrease by aprotinin and increased from 17.8 to 47.2 ng/ml/h (278.2%) by captopril (p < 0.05). Although the administration of captopril alone did not alter the renal hemodynamics despite the reduction of MBP, captopril made a recovery of renal plasma flow (RPF), CPF and NCPF which had decreased by aprotinin. Especially, CPF showed a significant recovery from 45.4 to 55.6 ml/min (123.6%) by captopril (p < 0.02). These results indicate that the inhibition of endogenous angiotensin made a preferential increase in CPF and suggest that the renin-angiotensin system plays a major role in the effect of captopril of the renal hemodynamic changes.