Analysis of human interindividual and racial differeness of drug response and metabolism : Approach by the method of diagnosis by gene analysis

药物反应和代谢的人类个体和种族差异分析：基因分析诊断方法

基本信息

批准号：
05454153
负责人：
KATO Ryuichi
金额：
$ 4.29万
依托单位：
Keio University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

项目摘要

Mephenytoin was administered to seven healthy volunteers of Japanese, and those were phenotyped extensive(EM)and poor metabolizers(PM)of mephenytoin 4'-hydroxylation.Six subjects were judged as EM,and one as PM.Twelve liver microsomal samples of Japanese and five samples of Caucasian were also phenotyped EM and PM by measuring R-and S-mephenytoin 4'-hydroxylation.Nine Japanese and five Caucasian subjects were judged as EM and three Japanese were PM.Genomic DNAs were isolated from nine EM and four PM,and DNA sequences were analyzed and the sequences of putative mephenytoin 4'-hydroxylases (CYP2C forms) were compared between EM and PM.No difference was observed on the sequences of CYP2C9/18 between EM and PM.Anucleotide substitution was detected in the sequence of exon 4 of CYP2C19 in PM,phenotyped in vivo.Another mutation was detected in the sequense of intron 4 just before exon 5 of CYP2C19 in PM,phenotyped in vitro.In either case, CYP2C19 does not express in PM livers, Metabolism of diazepam was studied in vitro by using liver microsomes obtained from EM and PM.The rate of diazepam N-demethylation was about one-third that of 3-hydoxylation at a high substrate concentration(0.2mM), however, the rate of N-demethylation increases with the decrease in the substrate concentration (-0.02mM).Diazepam N-demethylation seems to be mediated by CYP2C forms.On the other hand, diazepam 3-hydroxylation was selectively catalyzed by CYP3A forms.These results were consistent with the observation in vivo that diazepam N-demethylation and S-mephenytoin 4'-hydroxylation are closely correlated in humans.

Mephenytoin被给七名健康的日本志愿者，这些志愿者被表现为广泛的（EM）和不良的代谢剂（PM）4'-羟基化的代谢物（PM）。六个受试者被判断为EM，其中一个被视为PM.Tewelve Liver Liver Microsomal samples of。还通过测量R和s-甲状腺4'-羟基化来表型EM和PM样品。九种日语和五个高加索受试者被判断为EM，三个日语是PM.基因组DNA。分析了和DNA序列，并在EM和PM之间比较了假定的甲苯二酮4'-羟化酶（CYP2C形式）的序列。 CYP2C19的外显子4在PM中，体内表型。在pM中CYP2C19的外显子5之前的内含子4序列中检测到其他突变，在PM肝脏中均未表达CYP2C19的表型。通过使用从EM和PM获得的肝微粒体进行体外研究的。地西epam n-甲基化的速率约为高基质浓度下3-羟基化的三分之一，但是，N-甲基化的速率随着N-甲基化的速率随着N-甲基化的速率增加而增加。底物浓度（-0.02mm）的降低。Diazepamn-甲基化似乎是由CYP2C形式介导的。另一方面，地西epam 3-羟基化通过CYP3A形式选择性地催化这些结果。地西epam n-甲基化和s-甲基苯二甲基4'-羟基化在人类中密切相关。