TEMPERATURE-DEPENDENT PHOSPHOLIPID DEGRADATION IN THE RAT-LIVER DURING PRESERVATION FOR TRANSPLANTATION - A COMPARISON BETWEEN DIFFERENT PRESERVATION SOLUTIONS

For the development of liver injury during preservation for transplantation, phospholipid degradation may be of importance. We therefore measured the degradation of [H-3]-arachidonic acid (20:4)- and [C-14]-linoleic acid (18:2)-labeled phospholipids during cold and warm preservation of rat livers in Eurocollins, University of Wisconsin, or a recently developed dextrans-based solution. The amount of labeled phospholipids decreased with time during preservation at 37 degrees C with a concomitant increase in that of labeled fatty acids. The rate of degradation of [H-3]-20:4-labeled phospholipids did not differ from that of [C-14]-18:2-labeled phospholipids. The reduction of phosphatidylcholine and phosphatidylethanolamine radioactivity accounted for the major reduction of phospholipid radioactivity while there was no decrease in phosphatidylinositol radioactivity. In contrast, no phospholipid hydrolysis occurred during: preservation at 4 degrees C or at 21 degrees C. The results were not different whether the livers were preserved in EC, UW, or the dextran-based preservation solution. During reperfusion of livers either immediately after removal or after cold storage at 4 degrees C in EC or UW solutions for 24 hr, a moderate increase in the [H-3] and [C-14] radioactivity of free fatty acids and triacylglycerol and in that of [H-3] in PE occurred. There was, however, no difference between the three groups. Thus, during liver preservation at 37 degrees C, phospholipid degradation occurs, and its rate is independent of the preservation medium. In contrast, at the temperature used when preserving livers for transplantation, there is no phospholipid degradation. The cold storage in either EC or UW solution does not influence the net hydrolysis and the transesterification reaction that the phospholipids undergo during warm reperfusion of the isolated livers.