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 h epatocytes preserved (for 96 h at 4 degrees C) in University of Wiscon sin solution (UW solution) was analyzed. After this cold resuspension media storage, we evaluated the rewarming step (incubation time 120 mi n at 37 degrees C) using different pH levels (6.80, 7.00, 7.20, and 7. 40). Cell viability assessed by trypan blue exclusion (TEE) showed a s ignificant difference (p < 0.05) for cells incubated at pH = 7.20. For instance, TEE expressed as percent of change was 78.1 +/- 1.4 compare d with cells tested at other pH (pH = 6.80, TEE = 44.2 +/- 9.5; pH = 7 .00, TEE = 66.5 +/- 1.1 and pH = 7.40, TEE = 62.0 +/- 1.4). We also ev aluated the capacity of these cells both to maintain potassium content (0.509 +/- 0.230 mu Eq. K+/10(6) cells) and to synthesize urea (5.36 +/- 1.81 mu mol Urea/10(6) cells). These results were compared with th ose obtained from freshly isolated non preserved hepatocytes (0.518 +/ - 0.060 mu Eq. K+/10(6) cells and 5.91 +/- 0.43 mu mol Urea/10(6) cell s). The results show that viability is pH dependent and suggest that w hen resuspension media were used, the viability of hepatocytes was imp roved after 96 h of cold storage.