Protective effect of UW solution on postischemic injury in rat liver : Suppression of reduction in hepatic antioxidants during reperfusion

Preservation with University of Wisconsin (UW) solution can maintain liver graft function and produces survival rates of recipients higher than that with Euro Collins (EC) solution. To explore the underlying mechanisms, we transplanted rat livers following cold preservation with EC or UW solution for 18 hr, and measured hepatic adenine nucleotide levels, the percentage of water content, lactate levels, and endogenous antioxidant levels (alpha-tocopherol [alpha-Toc], reduced coenzyme Q9 [CoQ9H2], reduced coenzyme Q10, [CoQ1OH2] and reduced glutathione [GSH] during preservation and after transplantation. The adenosine triphosphate levels of the liver grafts preserved with UW solution recovered after reperfusion more rapidly and reached a higher level than those preserved with EC solution. UW solution caused a reduction in hepatic water content during preservation. Conversely, EC solution induced remarkable tissue edema. In addition, UW solution reduced the rate of hepatic lactate production both during preservation and after reperfusion. The concentrations of hepatic GSH, alpha-Toc, CoQ9H2, and CoQ1OH2 immediately after the graftectomy, and after the 18 hr of preservation with both EC and UW solutions, did not differ from those in the normal liver, and decreased only after transplantation. However, UW solution suppressed significantly the reduction in hepatic GSH, alpha-Toc, and CoQ9H2 after reperfusion, compared with EC solution. These results suggest that long-term cold storage induces tissue edema, reflecting a disturbance of the microcirculation during preservation, followed by parenchymal cell damage mediated by free radicals after reperfusion. The protective effects of UW solution could be attributable to the inhibition of free radical production after reperfusion.