Liu X, Chism J P, LeCluyse E L, Brouwer K R, Brouwer K L
Division of Drug Delivery and Disposition, School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7360, USA.
Drug Metab Dispos. 1999 Jun;27(6):637-44.
The relationship between biliary excretion in sandwich-cultured rat hepatocytes and in vivo in rats was examined. The biliary excretion of seven model substrates in 96-h sandwich-cultured rat hepatocytes was determined by differential cumulative uptake of substrate in the monolayers preincubated in standard buffer (intact bile canaliculi) and Ca2+-free buffer (disrupted bile canaliculi). Biliary excretion in vivo was quantitated in bile duct-cannulated rats. The biliary excretion index of model substrates, equivalent to the percentage of retained substrate in the canalicular networks, was consistent with the percentage of the dose excreted in bile from in vivo experiments. The in vitro biliary clearance of inulin, salicylate, methotrexate, [D-pen2,5]enkephalin, and taurocholate, calculated as the ratio of the amount excreted into the bile canalicular networks and the area under the incubation medium concentration-time profile ( approximately 0, approximately 0, 4.1 +/- 1.0, 12.6 +/- 2.2, and 56. 2 +/- 6.0 ml/min/kg, respectively), correlated with their intrinsic in vivo biliary clearance (0.04, 0, 17.3, 34.4, and 116.9 ml/min/kg, respectively; r2 = 0.99). The model compound 264W94 was not excreted in bile either in vivo or in vitro. The glucuronide conjugate of 2169W94, the O-demethylated metabolite of 264W94, was excreted into bile in vitro when 2169W94, but not 264W94, was incubated with the monolayers; 2169W94 glucuronide undergoes extensive biliary excretion after administration of 264W94 or 2169W94 in vivo. Biliary excretion in long-term sandwich-cultured rat hepatocytes correlates with in vivo biliary excretion. The study of biliary excretion of metabolites in the hepatocyte monolayers requires consideration of the status of metabolic activities.
研究了夹心培养的大鼠肝细胞中的胆汁排泄与大鼠体内胆汁排泄之间的关系。通过在标准缓冲液（完整胆小管）和无钙缓冲液（破坏的胆小管）中预孵育的单层细胞中底物的差异累积摄取，测定了96小时夹心培养的大鼠肝细胞中七种模型底物的胆汁排泄。在胆管插管的大鼠中定量体内胆汁排泄。模型底物的胆汁排泄指数，相当于小管网络中保留底物的百分比，与体内实验中胆汁排泄剂量的百分比一致。菊粉、水杨酸盐、甲氨蝶呤、[D-青霉胺2,5]脑啡肽和牛磺胆酸盐的体外胆汁清除率，计算为排泄到胆小管网络中的量与孵育培养基浓度-时间曲线下面积的比值（分别约为0、约为0、4.1±1.0、12.6±2.2和56.2±6.0 ml/min/kg），与它们的体内固有胆汁清除率相关（分别为0.04、0、17.3、34.4和116.9 ml/min/kg；r2 = 0.99）。模型化合物264W94在体内和体外均不排泄到胆汁中。当2169W94而非264W94与单层细胞孵育时，264W94的O-去甲基代谢产物2169W94的葡糖醛酸共轭物在体外排泄到胆汁中；在体内给予264W94或2169W94后，2169W94葡糖醛酸共轭物会进行大量胆汁排泄。长期夹心培养的大鼠肝细胞中的胆汁排泄与体内胆汁排泄相关。在肝细胞单层中研究代谢产物的胆汁排泄需要考虑代谢活性的状态。
