Evaluation of Drug-metabolizing enzyme activity and-drug interaction in paitients with hepatic disease

肝病患者药物代谢酶活性及药物相互作用评价

• 批准号: 12672224
• 负责人: YASUHARA Hajime
• 金额: $ 1.92万
• 依托单位: SHOWA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12672224/
• 关键词: Human liver; Hepatic cancer; CYP2C19; Cytochrome P-450; microsomes; CYP; Drug metabolism

Hepatic drug-metabolizing capacity mediated by cytochrome P450 is assayed in human surgical samples obtained from hepatocellular carcinoma (HCC) and metastatic cancer (MC) patients. Liver samples were donated from seven of HCC and four of MC patients. Each liver samples, apparently normal part, was used for the evaluation of drug metabolizing enzyme activity. Microsomal fraction was prepared by conventional method. Human pooled hepatic microsome from Caucasian brain death patients was employed as a reference enzyme source. Microsomal cytochrome P450 (CYP) enzyme activity, CYP1A2 (Caffeine, Ethoxyresorfin), 2C9 (Warfarin), 2C19 (Mephenytoin), 2D6 (Bufuralol), 2E1 (Chlorzoxazone) and 3A4 (Testosterone, Midazolam), were analysed by using typical substrates HPLC method was employed for the determination of each enzyme activity. CYP enzymes activity was variated from 2 to 5 fold in each CYP enzymes in both HCC and MC compared with pooled microsome CYPs activity. Furthermore, mean activity o … More f each CYP enzymes activity in HCC and MC liver samples compared with pooled microsomal CYP activities were quite similar in most of CYP enzymes. In CYP2C19, however, enzyme activity was quite low in both HCC and MC compared with pooled microsome. To clarify the mechanism of the expressed low activity of CYP2C19 in patient with hepatic disease, genetic profile and S-Mephenytoin 4'-hydroxylation activity in six of new patient's liver samples were analysed. Exon 4 and Exon 5 of CYP2C19 gene was analysed and all of patients has heterozygous for wild type and mutation in Exon 4 and three of 6 patients bad homozygous for mutation of Exon 5.Other 3 patients had wild type homozygous for Exon 5. Mephenytoin 4'-hydroxrylation activity was well correlated to genotype and normal level of the activity was observed in patients who has wild type homozygous in Exon 5 and quite low activity in 3 samples which has the homozygous for the mutation in Exon 5. These results in to consideration, low activity of CYP2C19 in patients with liver disease was due to the genetic deficiency of CYP2C19 gene on Exon 5.In general, 20 to 25% of again populations are genetically deficient of CYP2C19, however, in our results, quite high frequency of the enzyme deficiency was observed in patients with liver disease. These results may indicating that CYP2C19 deficiency reflect the one of the risk factor of liver disease such as hepatic cancer and/or liver cirrhosis. Less

在肝细胞癌和转移性癌患者的手术标本中，检测了细胞色素P450介导的肝脏药物代谢能力。肝脏样本来自7例肝细胞癌和4例肝细胞癌患者。每个肝脏样本，明显正常的部分，用来评估药物代谢酶的活性。用常规方法制备微体分数。以高加索脑死亡患者的人肝微粒体为参考酶来源。以典型底物为底物，分析了微粒体细胞色素P450(CYP)的酶活性，分别为咖啡因、乙氧基间苯二酚、2C9、2C19、2D6、2E1、3A4。在肝细胞癌和MC中，每种CYP酶的CYP酶活性与微粒子的CYP酶活性相比变化了2到5倍。此外，…的平均活性在肝细胞癌和MC肝组织中，每种CYP酶的活性与微粒体中的CYP活性相比，在大多数CYP酶中的活性非常相似。然而，在CYP2C19中，无论是在肝细胞癌还是在MC中，酶的活性都很低，与共用的微生物体相比。为探讨肝病患者肝脏细胞色素P450 2 C19活性低的机制，对6例新发患者的肝脏标本进行了基因图谱和S-美苯妥因4‘-羟化活性的分析。外显子4和外显子5分析发现，所有患者均为野生型杂合子和外显子4突变，6例患者中有3例为外显子5突变纯合子。另外3例患者为野生型外显子5纯合子。外显子5野生型纯合子患者的苯妥英4‘-羟基化活性与基因型密切相关，3例外显子5突变纯合子患者的活性较低，提示肝病患者的低活性是由于外显子5的遗传缺陷所致。20%至25%的Again人群存在CYP2C19基因缺陷，然而，在我们的结果中，在肝病患者中观察到相当高的酶缺陷频率。这些结果可能表明，CYP2C19缺乏反映了肝癌和/或肝硬变等肝病的危险因素之一。较少