EXPRESSION OF LIVER FUNCTIONS IN IMMORTALIZED RAT HEPATOCYTE CELL-LINES

The differentiated hepatic function of two rat liver cell lines, P9 an d SV40RH1, immortalised by transfection with SV40 DNA has been investi gated in terms of the glutathione synthesis, and the activities of gam ma-glutamyltransferase, glutaihione-S-transferase and UDP-glucuronosyl transferase. SV40RH1 is a highly differentiated cell line at early pas sage, but the expression of some aspects of its differentiated phenoty pe is unstable and some functions are lost by passage 12-13. P9 is a l ess-well differentiated cell line, with relatively stable expression o f functions between passages 4 and 13. In terms of differentiated func tion both cell lines represent a marked improvement over primary cultu res of rat hepatocytes which de-differentiate rapidly within 24-48 h i n culture. This retention of liver function in proliferating cell line s offers the opportunity to use such cells in in vitro toxicological s tudies.