Role of bradykinin in the antihypertensive and cardioprotective actions of converting enzyme inhibitors

Angiotensin converting enzyme inhibitors (ACEIs) not only reduce angiotensin II synthesis but also potentiate endogenous kinins. In addition to their antihypertensive actions, accumulated evidence has demonstrated an improvement by ACEIs of cardiac function, cardiac structural and metabolic status, and myocardial blood flow in conditions such as cardiac ischemia, left ventricular hypertrophy, and myocardial infarction. The mechanisms underlying the antihypertensive and cardioprotective actions of ACEIs are under intensive investigation. A reduction of angiotensin 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 antihypertensive actions of these drugs. In addition, experimental observations suggest that bradykinin potentiation plays a pivotal role in the cardioprotective effects of ACEIs.