Influence of superoxide dismutase on reperfusion injury in donor hearts preserved with Bretschneider-HTK cardioplegic solution.

The ability of superoxide dismutase to prevent reperfusion injury after long-term cold storage of donor hearts was evaluated in canine hearts. Whole blood reperfusion was performed using a 'support animal'. Twelve dog hearts were arrested by a single dose of Bretschneider cardioplegic solution and stored cold (0.5 degrees C) for 24 h. Thereafter they were reperfused for 60 min without (n = 6) or with (n = 6) superoxide dismutase treatment. Myocardial tissue biopsies were taken for determination of high-energy phosphates before explantation, after the preservation period and during reperfusion. Early reperfusion in both groups resulted in an initial recovery of high-energy phosphates and was followed by a decrease during the subsequent reperfusion phase. The latter was associated with the appearance of left ventricular contracture, and cessation of heart beat. Electron microscopic examination of the myocardial tissues after reperfusion revealed a severe reperfusion injury in both groups. It is concluded, that in donor hearts preserved with Bretschneider solution, reperfusion injury cannot be prevented by administration via the perfusate of superoxide dismutase.