The protective effect of angiotensin converting enzyme inhibitors (ACEI) on myocardial ischemia and reperfusion injury was estimated in the isolated working rat heart. Male Wistar rats were divided into four groups and reared for 6 weeks : fed without ACEI (Group A), fed with Captopril 30mg/kg/day (Group B), fed with Captopril 60mg/kg/day (Group C) and fed with Enalapril 20mg/kg/day (Group D). Isolated perfused rat hearts were ischemic for 20min at 37℃ and were reperfused for 30min at 37℃.
Addition of ACEI preserved cardiac output, prevented increase of coronary resistance and release of cardiac enzyme (CPK) in Group B,C,D hearts compared with Group A. These findings suggest that ACEI can protect the myocardium from ischemia and reperfusion injury by pretreatment.