Inhibition of Angiotensin I-Initiated Hemodynamic Changes in Anesthetized Dogs by a Synthetic Nonapeptide

Intravenous injections of SQ 20, 881, a competitive inhibitor of the angioten-sin-converting enzyme, suppressed the pressor and reduced renal blood flow responses initiated by the infusion of angiotensin I (50 to 100 ng/kg/min) into anesthetized dogs. Both the degree and duration of inhibition by SQ 20,881 were proportional to the dose of SQ 20,881 up to 300 μg/kg; this dose produced a maximal inhibition of about 80%, and an inhibition of at least 25% that lasted for approximately 2 hr.