Involvement of the renin-angiotensin system in ischemic damage and reperfusion arrhythmias in the isolated perfused rat heart.

We have investigated the contribution of the renin-angiotensin system to the damage caused by 40-min global ischemia in the isolated rat heart. A converting enzyme inhibitor, enalaprilat (70 nM), an angiotensin II receptor antagonist, compound 89 (2 μM), and an inhibitor of rat renin, CGP 44099 A (20 nM), given before ischemia reduced the median duration of ventricular fibrillation on reperfusion to a similar extent (5.53, 5.72, and 5.14 min, respectively, compared to 13.98 min in the control group) but had no effect on creatine phosphokinase release (22.2±2.6, 22.1±6.8, and 24.1±3.6, IU/30 min, respectively, compared to 19.9±1.9 IU/30 min) or recovery of left ventricular developed pressure (67±6,73±7 and 71±6%, respectively, compared to 66±3% after 30 min reperfusion). The increase in coronary resistance and left ventricular diastolic pressure on reperfusion was not affected by any of the agents