VIABILITY, ATTACHMENT EFFICIENCY, AND XENOBIOTIC-METABOLIZING ENZYME-ACTIVITIES ARE WELL MAINTAINED IN EDTA ISOLATED RAT-LIVER PARENCHYMAL-CELLS AFTER HYPOTHERMIC PRESERVATION FOR UP TO 3 DAYS IN UNIVERSITY-OF-WISCONSIN SOLUTION

Rat liver parenchymal cells were isolated by EDTA perfusion and were s ubsequently purified by Percoll centrifugation, The freshly isolated l iver cells had a mean viability of 95% as judged by trypan blue exclus ion, Isolated liver parenchymal cells were then stored at 0 degrees C for up to 1 wk in University of Wisconsin solution (UW). During this h ypothermic preservation, the viability was only slightly reduced to 99 % after 1 d and to 85% after 3 d at 0 degrees C. Thereafter, the viabi lity decreased rapidly. After cold storage for up to 3 d, it was possi ble to use the parenchymal liver cells either in short-term suspension or in cell culture. The attachment efficiency in cell culture was the same for freshly isolated liver cells (84%) and after 2 d cold preser vation (81%), The cytochrome P450 content and the enzyme activities of soluble epoxide hydrolase, UDP-glucuronosyl transferase, phenol sulfo transferase, and glutathione S-transferase were not significantly diff erent between freshly isolated cells and cells after 3 d of hypothermi c preservation. Furthermore, freshly isolated and intact liver cells s tored for 3 d were used in the cell-mediated Salmonella mutagenicity t est as a metabolizing system. Both fresh and stored liver parenchymal cells metabolized benzo(a)pyrene, 2-aminoanthracene, and cyclophospham ide to their ultimate mutagens, Thus, it was clearly demonstrated that EDTA-isolated liver parenchymal cells retain their xenobiotic metabol izing capacity after short-term hypothermic preservation for up to sev eral days and, therefore, may help to maximize the usefulness of rarel y available liver parenchymal cells such as those from humans and help to reduce the number of experimental animals required for pharmacolog ical and toxicological in vitro investigations.