Comparative effects of UW and SLS solutions on concentrative proline uptake in cold preserved rat hepatocytes

In previous studies, we have shown that the rate of cell swelling induced b y concentrative proline uptake in isolated rat hepatocytes decreased by 50 per cent after only 24 h of cold storage in University of Wisconsin (UW) so lution, thereby representing a sensitive marker of alterations in hepatocyt e functions after cold preservation and rewarming. We have thus used concen trative proline uptake to compare the capacity of UW and sodium-lactobionat e-sucrose (SLS) solutions to maintain such differentiated hepatocyte functi ons. Isolated rat hepatocytes were kept at 4 degrees C for 4, 10, 24 and 48 h in UW or SLS solutions, and subsequently cultured at 37 degrees C for 1- 2 h. Viability was measured by Trypan blue exclusion. After rewarming, cell s were subjected to a 10 min administration of 10 mM proline and accumulati on of the amino acid was assessed by changes in cell volume as measured by digital analysis of single-cell images obtained under bright-field illumina tion. Cell viability was reduced gradually and significantly after 0 to 48 h of preservation, and rewarming amplified this effect. However, loss of vi ability was similar in UW- and SLS-stored cells, as were initial steady-sta te cell volumes. Proline-induced swelling rate was reduced significantly by 13, 46 and by 57 per cent after 10, 24 and 48 h of preservation in UW solu tion, respectively. There is no significant difference between SLS and UW-p reserved hepatocyte swelling rates after 10 h and 45 h of cold preservation . However, the decline in the swelling rate of SLS-preserved hepatocytes in cubated for 24 h is significantly lower than that of their UW-preserved cou nterparts. These results show that the SLS solution can preserve differenti ated hepatic functions as well as the UW solution does.