Abstract
To determine the efficacy of MCI-186, a novel free radical scavenger, in ischemiareperfusion injury during cardiopulmonary bypass (CPB), the following experimental model was applied. Twenty-one mongrel dogs were subjected to 120 minutes of hypothermic global ischemia by aortic cross clamping with intermittent administration of a cardioplegic solution followed by 60 minutes reperfusion. They were assigned to three groups: group A(n=7), no drug was administered before reperfusion; group B(n=7), 1ml/kg of physiological saline was administered by bolus injection through the aortic root just before reperfusion; group C(n=7), MCI-186 (3mg/ml/kg) dissolved in physiological saline was administered in the same manner as group B. Cardiac function (left ventricular systolic pressure, cardiac output, left ventricular maximum dP/dt) after 60 minutes reperfusion expressed as a percent recovery of pre-ischemic state was superior in group C than in groups A and B. Release of lipidperoxide assayed by the TBA method as the difference between coronary artery and sinus were suppressed in the early phase of reperfusion in group C. Myocardial water content after 60 minutes reperfusion was also less in group C than in groups A and B. These findings suggest that administration of MCI-186 before reperfusion after ischemia is effective in protecting the heart from ischemia-reperfusion injury.
