The hydrophilic HMG-CoA reductase inhibitor pravastatin is not taken up via a carrier-mediated system into Hep G2 cells. Therefore, Hep G2 cells are not a good model for human hepatocytes with respect to elucidation of the effect of hydrophilic HMG-CoA reductase inhibitors. Sulfobromophthalein (BSP), on the other hand, is taken up into Hep G2 cells by carrier systems with Km and Vmax values almost identical to freshly isolated hepatocytes. These results indicate that the hepatocellular BSP transporting proteins expressed in Hep G2 cells (bilitranslocase and BSP/bilirubin binding protein) are not involved in the hepatocellular uptake of pravastatin. In contrast to the hepatocellular sodium-taurocholate cotransporter, which is not functioning in Hep G2 cells, we found a saturable transport of cholate with Km and Vmax values identical to those in cultured rat hepatocytes in the presence of sodium.