Blood pressure and renin responses to captopril in anesthetized rats pretreated with indomethacin or aprotinin

The present study was done to investigate the role of endogenous prostaglandins and kinins in the mechanism of captopril-induced hypotensive effect and stimulating effect of plasma renin activity (PRA) in pentobarbital-anesthetized rats. An intravenous injection of 1 mg/kg captopril significantly decreased mean blood pressure (MBP) and raised PRA. In indomethacin (5 mg/kg i.v.)- or aprotinin (50,000 kallikrein inhibitory units/kg and subsequent 100 k.i.u./kg·min, i.v.)-pretreated rats, MBP reduction and elevation of PRA induced by captopril were similar to those in the non-pretreated animals throughout the experimental periods. These results suggest that prostaglandins and/or the kallikrein-kinin system do not substantially participate in the captopril-induced hypotension and renin release under the present experimental conditions.