Individual Difference in Drug Metabolism and Disposition : Toxicological Significance of Genotypes and Phenotypes of S-mephenytoin 4'-hydroxylase(CYP2C19)

药物代谢和处置的个体差异：S-美芬妥英 4-羟化酶（CYP2C19）基因型和表型的毒理学意义

• 批准号: 11670416
• 负责人: JUN Ikebuchi
• 金额: $ 2.24万
• 依托单位: Tottori University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11670416/
• 关键词: drug metabolizing enzyme; cytochrome P-450; CYP2C19; genotype; phenotype; genetic polymorphism; individual difference; toxicology

The 4'-hydroxylation of S-mephenytoin has been shown to be mediated by CYP2C19. It is also important in the metabolism of a number of relatd hydantoins and barbiturates, as well as in that of structurally dissimilar drugs such as omeprazole, proguanil, and citalopram. As a result, large interphenotypic differences occur in the disposition of these drugs, which may affect their toxicity and efficacy.Therefore, we examined the relationship between genetic polymorphism of CYP2C19 and metabolism of omeprazole in order to assess the severity and to predict the outcome of poisoning for the forensic and clinical toxicology. In this study, we prepared the DNA samples from the blood of unrelated healthy Japanese, and developed a rapid and simple genotyping method using a polymerase chain reaction (PCR) based restriction fragment length polymorphism. Genotyping procedures for the identification of CYP2C19 were performed by PCR amplification with use of the allele-specific primers described by de Morais et al. with minor modifications. PCR products were digested with the restriction enzymes, and were analyzed by polyacrylamide gel electrophoresis. Furthermore, CYP2C19 phenotypes were determined by measuring omeprazole and hydroxyomeprazole concentrations in the serum, collected at 2 hours after omeprazole ingestion, by high performance liquid chromatography described by Marinac et al. with minor modifications. Consequently, the genotypes observed were CYP2C19^*1A (wild type : wt), CYP2C19^*2 (m1), and CYP2C19^*3 (m2). The omeprazole hydroxylation index of wild-type was -1.15, whereas hetero-type was -0.78, and homo-mutated type 1.22. The genotype of CYP2C19 correlated with the phenotype. These results proved that genotyping assays of drug metabolizing enzymes would play more important role in assessing the severity and predicting the outcome of poisoning for forensic and clinical toxicology.

已证明S-美芬妥英的4 '-羟基化由CYP 2C 19介导。在许多相关的乙内酰脲和巴比妥类药物的代谢中，以及在结构不同的药物如奥美拉唑、氯胍和西酞普兰的代谢中也很重要。因此，本研究旨在探讨CYP 2C 19基因多态性与奥美拉唑代谢的关系，为法医学和临床毒理学研究提供依据。在这项研究中，我们准备的DNA样本无关的健康日本人的血液，并开发了一种快速，简单的基因分型方法，使用聚合酶链反应（PCR）为基础的限制性片段长度多态性。使用de Morais et al.描述的等位基因特异性引物，通过PCR扩增进行CYP 2C 19鉴定的基因分型程序，并进行了微小修改。PCR产物用限制性内切酶消化，并通过聚丙烯酰胺凝胶电泳进行分析。此外，通过采用Marinac et al.描述的经微小修改的高效液相色谱法测量奥美拉唑摄入后2小时采集的血清中奥美拉唑和羟基奥美拉唑浓度，测定CYP 2C 19表型。因此，观察到的基因型为CYP 2C 19 ^*1A（野生型：wt）、CYP 2C 19 ^*2（m1）和CYP 2C 19 ^*3（m2）。野生型奥美拉唑羟化指数为-1.15，而杂合型为-0.78，同源突变型为1.22。CYP 2C 19基因型与表型相关。这些结果表明，药物代谢酶基因分型检测在法医学和临床毒理学中对中毒严重程度的评估和转归的预测将发挥更重要的作用。

项目成果

Jun Ikebuchi et al.: "Individual Difference in Drug Metabolism and Disposition : Toxicological Significance of Genotypes and Phenotypes of S-mephenytoin 4'-hydroxylase (CYP2C19)"Progress in Forensic Genetics, Ireland, Elsevier Scientific Publishers. (in p

Jun Ikebuchi 等人：“药物代谢和处置的个体差异：S-美芬妥英 4-羟化酶 (CYP2C19) 基因型和表型的毒理学意义”法医遗传学进展，爱尔兰，爱思唯尔科学出版社。

Jun Ikebuchi et al.: "Progress in Forensic Genetics(分担執筆)"Elsevier(in press). (2001)

Jun Ikebuchi 等人：“法医遗传学进展（合著者）”Elsevier（印刷中）。