CARDIOPLEGIC EFFECT OF UNIVERSITY-OF-WISCONSIN SOLUTION ON HYPOTHERMIC ISCHEMIA OF RAT MYOCARDIUM ASSESSED BY MITOCHONDRIAL OXIDATIVE-PHOSPHORYLATION

The effectiveness of the University of Wisconsin solution and the Coll ins' M solution for preservation of rat hearts was compared by examini ng histologic appearance, tissue water content, and mitochondrial resp iratory functions after prolonged hypothermic storage and subsequent h eterotopic transplantation. Survival of transplanted hearts after 5 da ys of reperfusion was markedly lowered by storage in Collins' M soluti on for 15 hours. Hearts stored in University of Wisconsin solution for 10 hours showed no increase in myocardial necrosis after 5 days of re perfusion, whereas hearts stored in University of Wisconsin solution f or 15 hours and Collins' M solution for 10 and 15 hours showed a signi ficant increase in tissue necrosis. University of Wisconsin solution r educed tissue swelling during hypothermic storage, whereas Collins' M solution did not cause such reduction. The yield of mitochondrial prot ein after reperfusion was significantly decreased by storage in either solution, especially after 15 hours in Collins' M solution. Mitochond rial oxidative phosphorylation was significantly inhibited by storage, especially by storage in Collins' M solution and subsequent reperfusi on. These results indicate that myocardial injury, after prolonged isc hemia and reperfusion, results in a decrease in functionally and struc turally intact mitochondria that is dependent on preservation conditio ns. University of Wisconsin solution protects isolated hearts against ischemia and reperfusion injury possibly by preventing cellular and mi tochondrial deterioration.