人肝细胞色素P450 2C8/9、2E1比活性测定

目的　建立甲苯磺丁脲羟化酶 (CYP2C8/ 9)和氯羟苯口恶唑 6 羟化酶 (CYP2E1)比活性的测定方法 ,为深入研究CYP45 0在药物代谢中的作用奠定基础。方法　从成人肝细胞中提取微粒体 ,测定其蛋白含量 ,以甲苯磺丁脲、氯羟苯口恶唑为底物 ,用HPLC以梯度洗脱法测定其代谢产物羟基甲苯磺丁脲及 6 羟基氯羟苯 口恶唑生成量 ,据此计算人肝细胞色素P45 0 (CYP45 0 )同工酶甲苯磺丁脲羟化酶 (CYP2C8/9)和氯羟苯 口恶唑 6 羟化酶 (CYP2E1)比活性。结果　于不同时间反复测定的CYP2C8/ 9、CYP2E1比活性无差异。结论　CYP2C8/ 9、CYP2E1的测定方法较为简单、稳定、重复性好 ,可用于新药筛选、安全性评价及肝脏病理学、毒理学研究。

Determination of the activity of human hepatic cytochromes P450 CYP2C8/9,CYP2E1

AIM To establish the methods for assaying the activities of tolbutamide hydroxylase (CYP2C8/9) and chlorzoxazone 6-hydroxylase(CYP2E1) from adult human livers microsomes. METHODS The microsomes was isolated from human adults liver and the contents of microsomal protein were determined. Using the tolbutamide and chlorzoxazone as substrates, the amount of hydroxytoblbutamide and hydroxychlorzoxazone formed during the incubation period was quantified by extroppolating from the standard curve and the specific activity of CYP2C8/9 and CYP2E1 were calculated. RESULTS There was no siginificant influence on the activities of CYP2C8/9 and CYP2E1 in different times. CONCLUSIONS The methods utilized to estimate the activity of CYP2C8/9 and CYP2E1 were simple, stable, and repeatable. These methods can be used in new drug screening, safety evaluation and reseasch on pathology and toxicology of liver.