硝克柳胺在大鼠和人肝脏的体外代谢研究

Metabolism of nicousamide in rat and human liver in vitro

研究硝克柳胺在大鼠肝微粒体和胞浆中的代谢动力学,鉴定硝克柳胺在大鼠和人肝微粒体中的主要代谢产物及参与代谢的药物代谢酶。采用高效液相色谱-紫外检测(HPLC-UV)方法测定大鼠肝微粒体和胞浆中硝克柳胺浓度,应用选择性抑制剂鉴定参与硝克柳胺代谢的药物代谢酶类型,采用液相色谱-串联质谱联用(LC-MS/MS)法分离鉴定硝克柳胺在大鼠和人肝微粒体中的主要代谢产物。硝克柳胺在大鼠和人肝微粒体的主要代谢产物(M1)为硝基还原产物[3-(3′-羧基-4′-羟基苯胺羰基)-6-氨基-7-羟基-8-甲基香豆素],大鼠体内(血浆、尿液、胆汁及肝组织)主要代谢产物与M1一致。硝克柳胺的体外代谢是依赖多个药物代谢酶参与的酶促反应,包括微粒体CYP450还原酶、细胞色素b5还原酶和CYP2C6以及胞浆NAD(P)H脱氢酶和黄嘌呤氧化酶。

This paper is aimed to study the metabolic kinetics of nicousamide in rat liver microsomes and cytosol and to identify the major metabolite and drug metabolizing enzymes involved in the metabolism of nicousamide in rat and human liver microsomes by selective inhibitors in vitro. The concentration of nicousamide was determined by HPLC-UV method. The metabolite of nicousamide in rat and human liver microsomes was isolated and identified by LC-MS/MS. The major metabolite of nicousamide in rat and human liver microsomes was identified to be 3-（ 3 ′-carboxy-4′-hydroxy-anilino-carbo-）-6-amino-7-hydroxy- 8-methyl-coumarin （M1）. The metabolite of nicousamide in rat plasma, urine, bile and liver was consistent with M1. The metabolism of nicousamide can be catalyzed by several reductases, including CYP450 reductases, cytochrome b5 reductases and CYP2C6 in rat liver microsomes, as well as xanthine oxidase and DT-diaphorase in rat liver cytosol.