ROLE OF BRADYKININ IN THE ANTIHYPERTENSIVE AND CARDIOPROTECTIVE ACTIONS OF CONVERTING-ENZYME INHIBITORS

Angiotensin converting enzyme inhibitors (ACEIs) not only reduce angio tensin II synthesis but also potentiate endogenous kinins. In addition to their antihypertensive actions, accumulated evidence has demonstra ted an improvement by ACEIs of cardiac function, cardiac structural an d metabolic status, and myocardial blood flow in conditions such as ca rdiac ischemia, left ventricular hypertrophy, and myocardial infarctio n. The mechanisms underlying the antihypertensive and cardioprotective actions of ACEIs are under intensive investigation. A reduction of an giotensin II synthesis is undoubtedly responsible for a major part of the antihypertensive effects of ACEIs. However, in experimental renal hypertension but not in genetic hypertension, bradykinin potentiation has been shown to partially mediate the acute and chronic antihyperten sive actions of these drugs. In addition, experimental observations su ggest that bradykinin potentiation plays a pivotal role in the cardiop rotective effects of ACEIs.