REDUCTION OF PROTEOLYSIS BY VENOUS-SYSTEMIC OXYGEN PERSUFFLATION DURING RAT-LIVER PRESERVATION AND IMPROVED FUNCTIONAL OUTCOME AFTER TRANSPLANTATION

An increase of cytosolic proteolytic activity during ischemic preserva tion and consecutive tissue degradation have recently been recognized as a major pathogenetic factor for liver injury during ischemia/reperf usion, In the present study, we propose a method for preventing proteo lytic tissue disintegration, which results in improved recovery of the liver after transplantation. Livers were harvested from rats and stor ed for 24 hr at 4 degrees C in University of Wisconsin solution (group A), Others were additionally persuffiated with gaseous oxygen via the inferior caval vein during this time (group B), At the end of ischemi c preservation, proteolysis was confirmed in group A, with significant ly elevated tissue levels of free alanine and free amino groups, where as proteolysis was prevented in group B, After transplantation, the in tegrity of the graft was significantly improved in group B, in which t here was a 50% reduction of plasma activities of alanine amino transfe rase and a twofold increase in hepatic bile production after the onset of reperfusion, as compared with group A. Moreover, venous-systemic o xygen persufflation during cold preservation significantly attenuated the rise in plasma levels of malondialdehyde (MDA) after liver transpl antation. In conclusion, venous systemic oxygen persufflation during i schemic storage prevents tissue proteolysis and reduces parenchymal in jury after transplantation in vivo; this technique may, thus, represen t a useful adjunct in long-term liver preservation with University of Wisconsin solution.