[Effect of intravenous recombinant human superoxide dismutase on reducing reperfusion injury]

This study was performed to evaluate effects of recombinant human superoxide dismutase (r-hSOD) administered intravenously just prior to reperfusion on reduction of reperfusion injury by using regional left ventricular function recovery in quantitatively controlled reperfusion model. Mongrel dogs underwent 2 hours of left anterior coronary artery clamping followed by 30 minutes of partial reperfusion (25% of control flow) and 30 minutes of full reperfusion (full opening of occluder). Regional left ventricular functions: % segmental shortening (%SS), % active shortening (%AS) = systolic shortening/total shortening, were evaluated during reperfusion. Dogs were divided into 2 groups, Control group and SOD group: r-hSOD was administered 100,000 Unit/kg in bolus intravenously before reperfusion. Measured left ventricular segments were classified by temperature drop in thermography into the central (> or = 2 degrees C) and the marginal (< 2 degrees C) ischemic zones. In the central ischemic zone, the values of %SS before left anterior descending coronary artery clamping were 11% and 12% in Control and SOD groups, respectively. Just after occlusion of coronary artery, %SS dropped down to the range of -5% to -7% and kept the same level during ischemia. After partial reperfusion, there was no significant difference of %SS between Control and SOD groups, however, after full reperfusion, %SS of SOD group showed better improvement than that of Control group (p < 0.05). As for %AS in the central ischemic zones, the same tendency was present. In the marginal ischemic zone, the values of %SS went down when left anterior descending coronary artery was occluded.(ABSTRACT TRUNCATED AT 250 WORDS)