HPLC法测定利多卡因及其代谢产物估算人肝微粒体CYP3A的活性

目的　以利多卡因 (LDC)与其代谢产物的比值估算人肝微粒体中CYP3A的活性。方法　以 1 0g·L- 1微粒体蛋白浓度 3 7℃孵育利多卡因 60min ,以HPLC测定利多卡因及其代谢产物单乙基甘氨二甲基苯酰胺 (MEGX)和甘氨二甲基苯酰胺 (GX)的含量。结果　LDC、MEGX和GX的标准曲线方程分别为 ^Y =0 2 93 4X -0 0 0 5661(r =0 9997)、^Y =0 7913X -0 0 0 8916(r =0 9993 )和 ^Y =0 6799X -0 0 0 7770 (r =0 9985)。体外孵育的最佳条件为 2 0mg·L- 1的LDC在浓度为 1 0 g·L- 1的微粒体中 ,孵育 60min ,代谢产物与利多卡因的平均比值为 3 2 8。结论　(MEGX +GX) /LDC可用来估算人肝微粒体CYP3A的活性。

Determination of lidocaine and its metabolites by HPLC to evaluate CYP3A activity of human liver microsomes

AIMTo evaluate CYP3A activity of hum an liver microsomes by the ratio of lidocaine(LDC) to its metabolites. M ETHODSIn 1 g·L -1 microsomal protein lidocaine was incubated at 37 ℃ for 1 hour. Lidocaine, monoethylglycinexylidide(MEGX) and glycinexylidide(GX) were determined by HPLC. RESULTSThe linear regress equations fo r LDC, MEGX and GX were = 0 293 4 X- 0 005 661 (r= 0 9 99 7 )、= 0 791 3 X- 0 008 916 (r= 0 999 3 ) and = 0 679 9 X- 0 007 770 (r= 0 998 5 ). The best conditio n for the incubation test in vitro was 2 0 mg·L -1 LDC plus 1 0 g ·L -1 microsomal protein for 60 min. The mean (MEGX+GX)/LDC ratio was 3 2 8. CONCLUSIONThe (MEGX+GX)/LDC ratio can be used to evaluate C YP3A activity of human liver microsomes.