人细胞色素P4503A活性测定

Determination of human cytochrome P450 3A activity

目的:建立测定人细胞色素P4503A酶活性的方法。方法:收集24h尿液,以HPLC法测定尿液中氢化可的松(HC)与6β-羟基氢化可的松(6β-OHC)的含量,以6β-OHC/HC来评估细胞色素P4503A酶的活性。结果:健康志愿者尿中6β-羟基氢化可的松和氢化可的松的比值为(8.5±3.0),肿瘤患者为(6.2±4.5)。结论:细胞色素P4503A酶的活性可以通过测定6β-OHC与HC的比值进行预测。

OBJECTIVE To establish a method for determining cytochrome P450 3A（CYP3A） enzyme activity. METHODS After collecting urine for 24 hours, the urinary concentrations of HC and 6β-hydroxycortisol（6β-OHC） were determined by high performance liquid chromatography（HPLC）. The ratio of 6β-OHC to HC has recently been demonstrated to be a specific marker for human CYP3A enzyme activity. RESULTS The ratio of 6β-OHC to HC was （8. 50 ±3.05） in volunteers, and （6. 23± 4. 54） in tumor patients. CONCLUSION The activity of CYP3A could be predicted by the 6β-OHC/HC ratio.