A SPECIFIC B2-BRADYKININ RECEPTOR ANTAGONIST HOE-140 ABOLISHES THE ANTIHYPERTROPHIC EFFECT OF RAMIPRIL

To evaluate the role of bradykinin in the antihypertrophic effect of t he angiotensin-converting enzyme (ACE) inhibitor, ramipril, we investi gated the influence of HOE 140, a specific B2-receptor antagonist, on the effects of ramipril on left ventricular hypertrophy (LVH) in rats with aortic banding. Ramipril at a dose of 1 mg kg-1 day-1 for 6 weeks prevented the increase in blood pressure and development of LVH after aortic banding; plasma ACE activity was significantly inhibited. A lo wer dose of ramipril (10-mu-g kg-1 day-1 for 6 weeks) had no effect on the increase in blood pressure or on plasma ACE activity, but prevent ed LVH after aortic banding. The antihypertrophic effects of the highe r and the lower dose ramipril, as well as the antihypertensive action of the higher dose of ramipril were abolished by the coadministration of HOE 140 (500-mu-g kg-1 day-1). The present data show for the first time that the beneficial effects of an ACE-inhibitor on LVH in rats wi th hypertension caused by aortic banding can be prevented by a specifi c B2-receptor antagonist.