Protective Effects of Lecithinized Superoxide Dismutase against Ischemia/Reperfusion Injury in Isolated Rat Heart

Protective Effects of Lecithinized Superoxide Dismutase against Ischemia/Reperfusion Injury in Isolated Rat Heart

(Department of Thoracic and Cardiovascular Surgery, Tohoku University, Sendai, Japan)

Makoto Kamada Atushi Iguchi Motohisa Tofukuji

Hitoshi Yokoyama Hiroji Akimoto Mikio Ohmi

Koichi Tabayashi

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 (n=5), the untreated control group, group II (n=5) received 3,000 units of L-SOD administered into the perfusion circuit at the beginning of reperfusion, and group III (n=5) received 3,000 units of L-SOD administered into the perfusion circuit 10 min after reperfusion. Left ventricular developed pressure, maximum positive and negative dp/dt, 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, p<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, p<0.01). The percent recovery of maximum negative dp/dt 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, p<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.　Jpn. J. Cardiovasc. Surg. 29: 315-319 (2000)