Ziegler K, Blumrich M, Hummelsiep S
Institute of Pharmacology and Toxicology, Justus-Liebig University, Giessen, Germany.
Biochim Biophys Acta. 1994 Sep 8;1223(2):195-201. doi: 10.1016/0167-4889(94)90226-7.
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.
亲水性HMG-CoA还原酶抑制剂普伐他汀不会通过载体介导的系统被摄取进入Hep G2细胞。因此,就阐明亲水性HMG-CoA还原酶抑制剂的作用而言,Hep G2细胞并非人类肝细胞的良好模型。另一方面,磺溴酞钠(BSP)通过载体系统被摄取进入Hep G2细胞,其Km值和Vmax值与新鲜分离的肝细胞几乎相同。这些结果表明,Hep G2细胞中表达的肝细胞BSP转运蛋白(胆红素转运体和BSP/胆红素结合蛋白)不参与普伐他汀的肝细胞摄取。与在Hep G2细胞中不起作用的肝细胞钠-牛磺胆酸盐共转运体相反,我们发现在有钠存在的情况下,胆酸盐的转运具有饱和性,其Km值和Vmax值与培养的大鼠肝细胞中的相同。