Assessment of multiple cytochrome P450 activities in metabolically inactivated human liver microsomes and roles of P450 2C isoforms in reaction phenotyping studies
Assessment of multiple cytochrome P450 activities in metabolically inactivated human liver microsomes and roles of P450 2C isoforms in reaction phenotyping studies
复制标题
代谢失活人肝微粒体中多种细胞色素 P450 活性的评估以及 P450 2C 亚型在反应表型研究中的作用
DOI：
10.1002/bdd.2115
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
H.
中科院分区：
文献类型：
--
作者：
Shimura;K.;Ishii;Y.;Takada;M.;Uno;Y.;Utoh;M.;Iwasaki;K.;and Yamazaki;H.
底物代谢的分数（fm）可用于估计药物相互作用，并可通过比较从抑制和未抑制的肝酶中获得的受害药物的内在清除率（克林特）来确定。这些灭活的肝微粒体用于评价P450 2C亚型在探针底物消耗和氧化中的作用。使用对照组和P450 2C 9灭活肝微粒体测定CLint，得出塞来昔布、双氯芬酸和华法林的fm、P450 2C 9值为0.69-1.0。在耗竭试验中观察到P450 1A 2/2C 8/3A 4的明显微小贡献，得出Fm值之和约为1。因此，选择性灭活的肝微粒体被证明是潜在的有用的测定thein主要P450 2C 9的底物氧化的体外fm值。用P450 2C 9灭活的肝微粒体替代对照肝微粒体，双氯芬酸和华法林的代谢物形成被抑制62-84%。在多种底物浓度下，肝微粒体对R-、S-和外消旋奥美拉唑和曲格列酮的氧化活性分别被抑制26-36%和22- 50%，当使用P450 2C 19-和2C 8-灭活肝微粒体代替对照肝微粒体时。这项研究提供了重要的信息，以帮助阐明不同的作用，P450异构体在代谢产物的形成，在不同的底物浓度。所获得的数据允许计算受害者药物的代谢分数。
The fraction of substrate metabolized (fm) can be used to estimate drug interactions and can be determined by comparison of the intrinsic clearances (CLint) of victim drugs obtained from inhibited and uninhibited hepatic enzymes.Commercially available human liver microsomes were recently developed in which one cytochrome P450 (P450) isoform is selectively inactivated. These inactivated liver microsomes were used to evaluate the roles of P450 2C isoforms in the depletion and oxidation of probe substrates. Determination of CLintwith sets of control and P450 2C9‐inactivated liver microsomes yielded fm,P450 2C9values of 0.69–1.0 for celecoxib, diclofenac and warfarin. Apparent minor contributions of P450 1A2/2C8/3A4 were seen in depletion assays, yielding ~1 for the sum of the fmvalues. Selectively inactivated liver microsomes were thereby shown to be potentially useful for determining thein vitrofmvalues for major P450 2C9 contributions to substrate oxidations. Metabolite formations from diclofenac and warfarin were suppressed by 62–84% by the replacement of control liver microsomes with P450 2C9‐inactivated liver microsomes.R‐,S‐ and racemic omeprazole and troglitazone oxidation activities by liver microsomes at multiple substrate concentrations were suppressed by 26–36% and 22–50%, respectively, when P450 2C19‐ and 2C8‐inactivated liver microsomes were used in place of control liver microsomes. This study provides important information to help elucidate the different roles of P450 isoforms in metabolite formation at different substrate concentrations. The data obtained allow the fractions metabolized to be calculated for victim drugs.