Akrawi M, Shephard E A, Phillips I R, Vercruysse A, Rogiers V
Department of Biochemistry and Molecular Biology, University College London, Gower Street, London WC1E 6BT, Belgium.
Toxicol In Vitro. 1993 Jul;7(4):477-80. doi: 10.1016/0887-2333(93)90050-f.
We have investigated, in hepatocytes co-cultured with epithelial cells, the effects of phenobarbital and sodium valproate treatment on members of the cytochrome P-450 superfamily. The expression of the P450IIB and P450IV families was examined, using Western blotting, at 4, 7 and 14 days of co-culture either in the presence or absence of drug treatment. The amount of P450IIB was increased after exposure of the co-cultured cells to either phenobarbital or sodium valproate. In contrast, P450IV amounts were increased only by sodium valproate treatment. The maximal induction of P450IIB (17-fold) was observed at 7 and 14 days of co-culture, whereas P450IV was induced to the same extent in cells co-cultured for 4, 7 and 14 days. We also examined the expression of these two cytochrome P-450 subfamilies in hepatocytes cultured for 4 days in the absence of epithelial cells. The amounts of both P450IIB and P450IV were low or undetectable in these cells, and the induction of these proteins by either phenobarbital or valproate was less than that observed in co-cultured hepatocytes. Our results demonstrate that the co-culture system is a suitable in vitro system for examining the effects of various foreign compounds on the expression of phase I drug metabolizing enzymes.
我们在与上皮细胞共培养的肝细胞中，研究了苯巴比妥和丙戊酸钠处理对细胞色素P - 450超家族成员的影响。在共培养的第4、7和14天，使用蛋白质免疫印迹法检测P450IIB和P450IV家族的表达，检测时分别处于有或无药物处理的条件下。将共培养的细胞暴露于苯巴比妥或丙戊酸钠后，P450IIB的量增加。相比之下，仅丙戊酸钠处理可使P450IV的量增加。在共培养的第7和14天观察到P450IIB的最大诱导倍数为17倍，而P450IV在共培养4、7和14天的细胞中诱导程度相同。我们还检测了在无上皮细胞条件下培养4天的肝细胞中这两个细胞色素P - 450亚家族的表达。在这些细胞中，P450IIB和P450IV的量都很低或无法检测到，并且苯巴比妥或丙戊酸对这些蛋白质的诱导作用小于在共培养肝细胞中观察到的效果。我们的结果表明，共培养系统是一种适用于检测各种外来化合物对I相药物代谢酶表达影响的体外系统。
