Effects of the Oral Converting Enzyme Inhibitor (SQ 14225) on One-Kidney Hypertension in the Dog

Abstract

Angiotensin blockade was produced 1 day before and for 7 days after renal artery stenosis in 3 unilaterally nephrectomized dogs by administration of SQ 14225 [D-3-mercapto-2-methylpropanoyl-L-proline]. The completeness of angiotensin blockade was demonstrated by reduced or absent pressor responses to exogenous angiotensin I and by a normal plasma aldosterone level after renal artery stenosis. A depressor response (9 mm Hg) during the day before renal artery constriction and markedly exaggerated depressor responses to exogenous bolus injections of bradykinin after several days of SQ 14225 administration might reflect an increased plasma level of bradykinin, but additional studies are needed on this idea. The arterial pressure response to renal artery constriction was markedly diminished during SQ 14225 and arterial pressure was not significantly elevated until the 5th day. PRA [plasma renin activity] was elevated throughout the period of SQ 14225 administration and renal artery constriction. The renin-angiotensin system need never be activated for the development and maintenance of chronic 1 kidney renovascular hypertension.