Cytochrome P-450 content and activity after cold storage of rat hepatocytes in university of wisconsin and sodium-lactobionate-sucrose solutions.

Abstract

We compared the capacity of University of Wisconsin (UW) and of sodium-lactobionate-sucrose (SLS) hypothermic preservation solutions to maintain the integrity of the hepatic cytochrome P-450-dependent mono-oxygenase system. Isolated rat hepatocytes were stored for 0, 10, 24, and 48 hours in UW or SLS solution and were subsequently cultured shortly at 37 degrees C. Cell viability declined slightly but significantly in a time-dependent manner during cold preservation in either UW or SLS solution, and warm culture exacerbated this effect. Total cytochrome P-450 declined gradually after cold preservation and warm culture to reach values of 70% and 52% of unstored controls in cells preserved for 24 and 48 hours in cold UW solution, respectively. Storage in cold SLS solution yielded a similar decrease to 79% and 59% of unstored controls for the equivalent preservation times. Cytochrome P-450 activity was assessed by the metabolism of theophylline after various cold preservation times in UW or SLS solutions. Production of the major metabolite 1,3-dimethyluric acid was not significantly affected by extended cold preservation periods in either UW or SLS solutions. Similarly, the amount of residual theophylline remained stable in all groups, suggesting that alternative metabolic routes were not modified. These studies show that cold preservation in SLS solution is as effective as that in UW solution in terms of cell viability, cytochrome P-450 content, and activity toward theophylline. In addition, the significant reduction in cytochrome P-450 in conjunction with unaffected theophylline disposition suggests that certain cytochrome P-450 isoforms are specifically damaged by cold preservation and rewarming.