Characterization of rat and human liver microsomal cytochrome P-450 forms involved in nifedipine oxidation, a prototype for genetic polymorphism in oxidative drug metabolism.
Characterization of rat and human liver microsomal cytochrome P-450 forms involved in nifedipine oxidation, a prototype for genetic polymorphism in oxidative drug metabolism.
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发表时间：
1986-04
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通讯作者：
F. Guengerich;M. Martín;P. Beaune;P. Kremers;T. Wolff;D. Waxman
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作者：
F. Guengerich;M. Martín;P. Beaune;P. Kremers;T. Wolff;D. Waxman
据报道，二氢吡啶类钙拮抗剂和血管扩张剂硝苯地平的代谢在人类个体中表现出多态性（Kleinbloesem，C. H、货车Brummelen，P.，Faber，H.，Danhof，M.，Vermeulen，N.体育课，和Breimer，D. D.（1984）Biochem.Pharmacol. 33，3721-3724）。硝苯地平氧化已被证明是由细胞色素P-450（P-450）酶催化。大鼠肝脏的复溶、免疫抑制和诱导研究表明，指定为P-450 UT-A和P-450 PCN-E的形式是微粒体硝苯地平氧化的主要贡献者。氧化硝苯地平的P-450（P-450 NF）从几个人肝样品中纯化至电泳均一。免疫印迹分析表明，P-450 NF抗体具有高度特异性，并抑制人肝微粒体中硝苯地平氧化酶活性的90%以上。针对人P-450制备物的单克隆抗体与人P-450 NF和大鼠P-450 PCN-E均发生反应。使用抗P-450 NF抗体对39份人肝微粒体样品进行免疫印迹分析，发现相同的52，000-道尔顿多肽，对应于P-450 NF，只有一份微粒体样品显示出额外的免疫反应性蛋白。硝苯地平氧化酶活性的水平与P-450 NF的量高度相关，因此使用多克隆（r = 0.78）或单克隆（r = 0.65）抗体检测，这表明P-450 NF多肽的量可能是影响人以及大鼠中催化活性水平的主要因素。在人肝微粒体中，细胞色素b5增强重组P-450 NF的催化活性，抗细胞色素b5抑制硝苯地平氧化酶活性。P-450 NF似乎也是人肝微粒体艾氏剂环氧化、d-苄非他明N-去甲基化、17 β-雌二醇2-和4-羟基化和睾酮6 β-羟基化的主要贡献者，睾酮6 β-羟基化是人肝微粒体中该雄激素氧化的主要途径。
The metabolism of the dihydropyridine calcium antagonist and vasodilator nifedipine has been reported to exhibit polymorphism among individual humans (Kleinbloesem, C. H., van Brummelen, P., Faber, H., Danhof, M., Vermeulen, N. P. E., and Breimer, D.D. (1984) Biochem. Pharmacol. 33, 3721-3724). Nifedipine oxidation has been shown to be catalyzed by cytochrome P-450 (P-450) enzymes. Reconstitution, immunoinhibition, and induction studies with rat liver indicated that the forms designated P-450UT-A and P-450PCN-E are the major contributors to microsomal nifedipine oxidation. The P-450 which oxidizes nifedipine (P-450NF) was purified to electrophoretic homogeneity from several human liver samples. Antibodies raised to P-450NF were highly specific as judged by immunoblotting analysis and inhibited greater than 90% of the nifedipine oxidase activity in human liver microsomes. A monoclonal antibody raised to the human P-450 preparation reacted with both human P-450NF and rat P-450PCN-E. Immunoblotting analysis of 39 human liver microsomal samples using anti-P-450NF antibodies revealed the same 52,000-dalton polypeptide, corresponding to P-450NF, with only one of the microsomal samples showing an additional immunoreactive protein. The level of nifedipine oxidase activity was highly correlated with the amount of P-450NF thus detected using either polyclonal (r = 0.78) or monoclonal (r = 0.65) antibodies, suggesting that the amount of the P-450NF polypeptide may be a major factor in influencing the level of catalytic activity in humans as well as rats. Cytochrome b5 enhanced the catalytic activity of reconstituted P-450NF, and anti-cytochrome b5 inhibited nifedipine oxidase activity in human liver microsomes. P-450NF also appears to be a major contributor to human liver microsomal aldrin epoxidation, d-benzphetamine N-demethylation, 17 beta-estradiol 2- and 4-hydroxylation, and testosterone 6 beta-hydroxylation, the major pathway for oxidation of this androgen in human liver microsomes.