Importance of pH in Resuspension Media on Viability of Hepatocytes Preserved in University of Wisconsin Solution

The effect of different pH of resuspension media on the viability of hepatocytes preserved (for 96 h at 4°C) in University of Wisconsin solution (UW solution) was analyzed. After this cold resuspension media storage, we evaluated the rewarming step (incubation time 120 min at 37°C) using different pH levels (6.80, 7.00, 7.20, and 7.40). Cell viability assessed by trypan blue exclusion (TBE) showed a significant difference (p < 0.05) for cells incubated at pH = 7.20. For instance, TBE expressed as percent of change was 78.1 ± 1.4 compared with cells tested at other pH (pH = 6.80, TBE = 44.2 ± 9.5; pH = 7.00, TBE = 66.5 ± 1.1 and pH = 7.40, TBE = 62.0 ± 1.4). We also evaluated the capacity of these cells both to maintain potassium content (0.509 ± 0.230 μEq. K+/106 cells) and to synthesize urea (5.36 ± 1.81 μmol Urea/106 cells). These results were compared with those obtained from freshly isolated non preserved hepatocytes (0.518 ± 0.060 μEq. K+/106 cells and 5.91 ± 0.43 μmol Urea/106 cells). The results show that viability is pH dependent and suggest that when resuspension media were used, the viability of hepatocytes was improved after 96 h of cold storage.