GLUTATHIONE MOVEMENTS DURING COLD PRESERVATION OF RAT HEPATOCYTES

In this study we have examined the movements of glutathione (GSH) duri ng cold preservation of rat hepatocytes in University of Wisconsin sol ution. During the preservation process at a low temperature (4 degrees C), with a high extracellular potassium concentration, an extracellul ar nondiffusible anion (lactobionate), and a Cl--free medium, there is a depletion of metabolites and the development of a time-dependent in jury. Also, there is a loss of GSH that is nor compensated by transpor t or synthesis and is basically due to increased catabolic processes. This sensitizes the cells to different forms of oxidative injury, whic h can play a negative role during transplantation. The addition of GSH improves liver cell preservation but the mechanism is unclear. To elu cidate this process we have isolated hepatocytes and preserved them un der different conditions: with or without GSH: in the presence of DL-b uthionine-[S,R]-sulfoximine, an inhibitor of glutathione synthetase, a nd acivicine to inhibit the ectoactivity of cellular gammaglutamyl tra nspeptidase: or by obtaining hepatocytes from rats depleted of GSH by an injection of diethyl maleate. Under all these conditions we evaluat ed the GSH content of the cells during cold storage. We also report th e time course of accumulation of [glycine-2-H-3]GSH. Our results show that during hypothermic storage in University of Wisconsin solution, h epatocytes are permeable to GSH, and the mechanism involved is a rapid nonsaturable process, with linear dependence of the extracellular GSH concentration, This finding may have valuable applications in the imp rovement of the delivery of compounds to cells. (C) 1998 Academic Pres s.