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

Abstract

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 K m and V max 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 K m and V max values identical to those in cultured rat hepatocytes in the presence of sodium.