Protective Effects of Lecithinized Superoxide Dismutase against Ischemia/Reperfusion Injury in Isolated Rat Heart / 日本心臓血管外科学会雑誌

ABSTRACT

Lecithinized superoxide dismutase (L-SOD) has a higher affinity for cell membranes than recombinant human superoxide dismutase has. The purpose of this study, is to evaluate the protective effects of L-SOD against ischemia/reperfusion injury in blood-perfused isolated rat heart subjected to 30-min global normothermic ischemia. Fifteen isolated hearts were divided into three groups group I (<i>n</i>=5), the untreated control group, group II (<i>n</i>=5) received 3, 000 units of L-SOD administered into the perfusion circuit at the beginning of reperfusion, and group III (<i>n</i>=5) received 3, 000 units of L-SOD administered into the perfusion circuit 10min after reperfusion. Left ventricular developed pressure, maximum positive and negative d<i>p</i>/d<i>t</i>, coronary vascular resistance and myocardial water content were assessed in each group. The percent recovery of left ventricular developed pressure in group II was significantly higher than that in group I and group III (77.4±11.1% in group II, 38.2±4.4% in group I, 40.2±4.1% in group III, <i>p</i><0.01). The percent recovery of maximum positive dp/dt in group II was significantly higher than that in group I and group III (70.0±11.2% in group II, 41.8±7.8% in group I, 38.0±5.7% in group III, <i>p</i><0.01). The percent recovery of maximum negative d<i>p</i>/d<i>t</i> in group II was also significantly higher than that in group I and group III (74.9±11.0% in group II, 41.3±8.0% in group I, 46.3±5.9% in group III, <i>p</i><0.01).There was no significant difference of coronary vascular resistance or myocardial water content among the three groups. These results suggest that L-SOD administered at the time of reperfusion has protective effects against ischemia/reperfusion injury in the isolated rat heart.