Effect of Supplementation of University of Wisconsin Solution with Glycoproteins from Psychrophilic Strains of Yeast on Hypothermic Liver Storage of Rats

Abstract

Extracellular yeast glycoproteins (YG) produced byRhodosporidium toruloideshave been shown to increase the survival rate of different yeast species after storage in liquid nitrogen. The purpose of this study was to investigate the effect of YG on cold-stored rat livers. Water-soluble YG produced either byPhaffia rhodozyma(G3) or byLeucosporidium antarcticum(G4) were added to a modified University of Wisconsin solution (mUW) and used for cold storage (1°C) of isolated livers. The functional status of each liver was then assessed under conditions of 90-min normothermic reperfusion. The 46-h cold storage in mUW without G3 and G4 resulted in serious preservation–reperfusion injury of the liver. The addition of G3 to mUW for 46-h preservation of the liver resulted in significantly higher bile flow (4.32 ± 0.35 vs 2.35 ± 0.49 μl/min/10 g at 75–90 min), higher portal blood flow (10.99 ± 0.2 vs 4.78 ± 1.07 ml/min/g at 90 min), lower liver weight after reperfusion (102.4 ± 1.5 vs 116.7 ± 6.6% of weight before preservation), and lower total tissue water after reperfusion (2.49 ± 0.05 vs 2.92 ± 0.13 g water/g dry weight). However, the activity of ALT, AST, and LDH in perfusate was not changed. The beneficial effect of G4 was less pronounced. The 24-h storage in mUW resulted in a significant increase of AST and LDH activity in perfusate; the addition of G3 to mUW for 24-h preservation did not affect these parameters. In conclusion, the addition of 0.05% G3 or G4 to mUW was only partially beneficial in improving rat liver preservation.