Injury to Cultured Liver Endothelial Cells After Cold Preservation: Mediation by Reactive Oxygen Species that are Released Independently of the Known Trigger Hypoxia/Reoxygenation

When cultured liver endothelial cells were incubated in cold University of Wisconsin (UW) solution under hypoxic conditions, 3 ± 2% of cells had lost viability after 25 h. Simulating reperfusion by returning the cells to normal cell culture conditions increased the injury to 30 ± 11% after 3 h of recultivation. An injury of similar time course was observed after cold normoxic incubation in UW solution when the loss of viability increased from 20 ± 5% after the cold incubation to 60 ± 8% during a 3 h recultivation period. The loss of viability during recultivation was decreased by hypoxia, by the addition of 5,5-dimethyl-1-pyrroline N-oxide or of dimethyl sulfoxide to the cell culture medium, or by preincubating the cells with deferoxamine. The injury was accompanied by lipid peroxidation and was dependent on the period of cold incubation in UW solution. These results suggest the occurrence of a cold-preservation-induced “recultivation injury” mediated by reactive oxygen species. This cold-preservation-induced injury—occurring independently of hypoxia/reoxygenation—is likely to constitute an additional component of reperfusion injury after cold preservation of the liver.