HPLC直接进样测定咖啡因代谢物评价三种药物代谢酶活性  

Determination of five metabolites of caffeine in urine to assess three drug-metabolying biotransformation enzyme activities by HPLC with direct injection method

作　　者：李军[1] 彭向前[2] 张鉴[1] 郭瑞臣 

机构地区：[1]山东省立医院临床药理中心 [2]山东大学药学院 [3]齐鲁医院药物监测中心

出　　处：《中国临床药理学与治疗学》2005年第7期768-771,共4页Chinese Journal of Clinical Pharmacology and Therapeutics

基　　金：山东省自然科学基金(№Q99C05);山东省卫生厅科研项目(№1998CA1DBB5)

摘　　要：目的:建立测定尿中咖啡因的5种主要代谢物:5-乙酰氨基-6-甲酰氨基-3-甲基尿酸(AFMU)、1-甲基尿酸(1U)、1-甲基黄嘌呤(1X)、1,7-二甲基尿酸(17U)和1,7-二甲基黄嘌呤(17X)的高效液相色谱法,以评价N-乙酰基转移酶(NAT2)、细胞色素P450酶1A2(CYP1A2)和黄嘌呤氧化酶(XO)三种药物代谢酶的活性。方法:采用反相高效液相梯度洗脱法直接进样测定尿液内咖啡因代谢产物AFMU、1U、1X、17U和17X的相对含量,计算AFMU/(AFMU+1X+1U)(、AFMU+1X+1U)/17U和1U/(1X+1U),绘制概率分布直方图,分别反映NAT2、CYP1A2和XO的活性。结果:NAT2活性呈两态分布,快、慢乙酰化代谢表型的临界点为0.26,CYP1A2和XO酶活性呈近似正态分布。结论:本方法简便、准确、快速,适合于尿中咖啡因代谢物的测定及NAT2、CYP1A2和XO等药物代谢酶活性的研究。AIM： To establish a HPLC method with direct injection for determining five major metabolites of caffeine including 5-acetylamino-6-formylamino-3-methyluracil （AFMU）, 1-methylxanthine （1X）, 1-methyluric acid （1U）, 1,7-dimethyluricacid （17U） and 1,7-dimethylxanthine （17X） in the urine and assess the activities of N -acetyhransferase （ NAT2 ）, cytochrome P4501A2 （CYP1 A2 ） and xanthine oxidase （XO）. METHODS： The contents of five major metabolites of caffeine in the urine were determined by RP-HPLC method. Frequency distribution histogram were drawn by calculating the AFMU/（AFMU＋1X＋ 1U） ,（AFMU＋ 1X＋ 1U）/17U and 1U/（ 1X ＋ 1U） and then evaluated the activity of NAT2, CYP1A2 and XO, respectively. RESULTS： The frequency distribution histograms of NAT2 indicated two distinct distibution, and the subjects were classified as slow acetylators if PAR 〈 0.26 or as fast if PAR 〉 0.26. The frequency distribution of CYP1A2 and XO histograms indicated normal distribution. CONCLUSION： The method is simple, accurate, rapid, and suitable for the determination of metabolites of caffeine in urine. The method can be used to assay the activities of NAT2, CYP1 A2 and XO.

关 键 词：咖啡因代谢物 高效液相色谱法 N-乙酰基转移酶 细胞色素P450酶1A2 黄嘌呤氧化酶 

分 类 号：R969.1[医药卫生—药理学]