Oxygen-free radical-mediated injury to cultured rat hepatocytes during cold incubation in preservation solutions

We have previously shown that the injury to cultured liver endothelial cells during cold incubation in University of Wisconsin (UW) solution is energy-dependent and is mediated by reactive oxygen species. Here we demonstrate that this reactive oxygen-mediated injury is specific neither to endothelial cells nor to UW solution: cultured hepatocytes incubated in cold (4 degrees C) UW solution or histidine-tryptophan-ketoglutarate (HTK) solution were injured under normoxic conditions (loss of viability, 63% +/- 10% after 48 hours of cold incubation in UW solution and 82% +/- 11% after 24 hours of cold incubation in HTK solution), whereas hypoxia was protective (loss of viability, 29% +/- 12% [UW] and 13% +/- 3% [HTK] after the same cold incubation times). The injury under normoxic conditions was also largely decreased by adding either the spin trap 5,5-dimethyl-l-pyrroline N-oxide (DMPO) or the flavonoid silibinin to the solutions, or by preincubating the cells with the iron chelator deferoxamine before the hypothermic incubation. Marked lipid peroxidation was observed during cold incubation in both preservation solutions. These results suggest that the injury to cultured hepatocytes during cold incubation in UW and HTK solutions is mediated by reactive oxygen species as is the injury to cultured liver endothelial cells.