THE TRANSPORTER FOR THE HMG-COA REDUCTASE INHIBITOR PRAVASTATIN IS NOT PRESENT IN HEP G2 CELLS - EVIDENCE FOR THE NONIDENTITY OF THE CARRIER FOR PRAVASTATIN AND CERTAIN TRANSPORT-SYSTEMS FOR BSP

The hydrophilic HMG-CoA reductase inhibitor pravastatin is not taken u p via a carrier-mediated system into Hep G2 cells. Therefore, Hep G2 c ells are not a good model for human hepatocytes with respect to elucid ation of the effect of hydrophilic HMG-CoA reductase inhibitors. Sulfo bromophthalein (BSP), on the other hand, is taken up into Hep G2 cells by carrier systems with K-m and V-max values almost identical to fres hly isolated hepatocytes. These results indicate that the hepatocellul ar BSP transporting proteins expressed in Hep G2 cell (bilitranslocase and BSP/bilirubin binding protein) are not involved in the hepatocell ular uptake of pravastatin. In contrast to the hepatocellular sodium-t raurocholate cotransporter, which is not functioning in Hep G2 cells, we found a saturable transport of cholate with K-m and V-max values id entical to those in cultured rat hepatocytes in the presence of sodium .