Protective effects of superoxide dismutase against oxygen toxicity in rat's heart lung preparation.

Oxygen toxicity in the non-ischemic and non-hypoxic heart has not been reported. In an experiment on isolated rat heart lung preparation, the effects of superoxide dismutase (SOD) on oxygen toxicity during hyperoxic perfusion were evaluated with intramyocardial high energy phosphates and the release of creatine phosphokinase (CPK) in the perfusate blood. Although there were no significant differences in high energy phosphates between SOD-treated and untreated hearts, the CPK release from the SOD-treated hearts was significantly less than from the untreated hearts. SOD increased the oxygen pressure of perfusate blood, too. These results indicate that hyperoxia induced cardiac and lung cell damage which was protected by SOD.