【摘要】 目的以细胞色素P450(CYP)3A探针药物咪哒唑仑(MDZ)的系统清除率(CLs)为指标,评价有限采样法(LSS)预测肝脏损伤状态下CYP3A代谢活性的可行性。方法采用系列浓度的四氯化碳溶液预处理大鼠,24h后,静脉注射MDZ,在若干时间点采血检测血浆MDZ浓度。留取血清并检测丙氨酸氨基转移酶(ALT)和天冬氨酸氨基转移酶(AST)活性。经逐步回归分析和Jack-knife方法验证,建立最终的LSS模型。对经相同处理的另一随机群体进行验证分析,评价该LSS模型方程的准确性和重现性。结果系列浓度四氯化碳溶液造成肝脏不同程度损伤。由单点(45min)或两点(5,45min)血浆药物浓度建立的LSS预测模型所得到的CLs估计值(CLest)与实际计算值(CLobs)之间具有良好的相关性,误差小。两点LSS模型对样本预测的相关性较单点LSS更优(r=0.96),而单点LSS模型则更显简便。结论本实验表明,以MDZ清除率为指标,采用45min或5.45min的有限采样方案评价肝脏损伤状态下CYP3A的代谢活性是一种准确而简便的方法,为今后推广到临床评价肝脏代谢功能从而制定和调整给药方案提供了理论依据和实验室证据。更多还原

【Abstract】 OBJECTIVE To evaluate the feasibility of a limited sampling strategy (LSS) for the prediction of damaged hepatic CYP3A activity by the systemic clearance of midazolam (MDZ),a CYP3A phenotyping probe. METHODS Rats pretreated with or without serial concentrations of carbon tetrachloride( CCl4) solutions were used as training set. After 24 h,the activities of serum ALT and AST were detected. Linear regression analysis and a Jack-knife validation procedure was performed based on plasma MDZ concentrations at specific times after sublingual vein injection of MDZ to establish the most informative LSS equations for accurately estimating the clearance of MDZ. Another rats in the same setting was used as the validation set to confirm the individual values of estimated clearance (CLest) that were derived from the predictive equations developed in the training set. RESULTS Series of CCl4 solutions induced different degree of liver injury. LSS models derived from single or two sampling time points,at 45 min and 5.45 min,exhibited a good accuracy and acceptable error for estimating the CLobs of MDZ to evaluate hepatic CYP3A activity,especially the 5.45 min LSS model showed more accurate. CONCLUSION The results support the hypothesis that limited sampling strategy is less complicated than the usual method for estimating hepatic CYP3A phenotyping by predicting the systemic clearance of MDZ clearance when liver is damaged in rats. The present study provided theoretical basis and laboratory evidence for LSS to clinically evaluate metabolizing function of liver and design rational drug regimen.更多还原