CYP3A4/5 Activity Probed with Testosterone and Midazolam: Correlation between Two Substrates at the Microsomal and Enzyme Levels.
CYP3A4/5 Activity Probed with Testosterone and Midazolam: Correlation between Two Substrates at the Microsomal and Enzyme Levels.
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DOI：
10.1021/acs.molpharmaceut.8b01043
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发表时间：
2018-12
影响因子：
4.9
通讯作者：
K. Xiao;Jie Gao;Shi-Jia Weng;Yan Fang;Na Gao;Qiang Wen;Han Jin;Hailing Qiao
中科院分区：
文献类型：
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作者：
K. Xiao;Jie Gao;Shi-Jia Weng;Yan Fang;Na Gao;Qiang Wen;Han Jin;Hailing Qiao
替吉奥（TST）和咪达唑仑（MDZ）被广泛用作检测CYP 3A 4/5活性的探针，但用这两种底物获得的数据在微粒体水平（每毫克微粒体蛋白）相关性不好，原因尚不清楚。在本研究中，使用TST和MDZ在72份人肝脏样本的微粒体和酶水平（每皮摩尔CYP 3A 4/5）探测CYP 3A 4/5活性。微粒体水平Vmax和克林特的相关系数低于酶水平（Vmax 0.658 vs 0.883;克林特无相关性vs 0.796）。与TST相比，MDZ与CYP 3A 4/5和CYP 3A 5的相关性更好（相关系数分别为0.431和0.447），且不同基因型间酶含量差异较大，说明MDZ与CYP 3A 4/5和CYP 3A 5的相关性较低。此外，不同基因型对酶活性的影响不同，但TST和MDZ探针酶活性差异不显著（P > 0.05），表明基因多态性对两种底物探针酶活性相关性的影响仅限于酶水平。总之，我们的研究表明，CYP 3A 4/5活性与TST和MDZ探测在酶水平，而不是在微粒体水平的高度相关性，使我们能够正确地理解基因多态性的相关性的影响。
Testosterone (TST) and midazolam (MDZ) are widely used as probes to detect CYP3A4/5 activity, but the data acquired with these two substrates do not correlate well at the microsomal level (per milligram of microsomal protein), and the reason is unclear. In this study, CYP3A4/5 activity was probed with TST and MDZ at the microsomal and enzyme levels (per picomole of CYP3A4/5) in 72 human liver samples. Correlation coefficients were lower in Vmax and CLint at the microsomal level, as compared with those at the enzyme level ( Vmax 0.658 vs 0.883; CLint no correlation vs 0.796). Compared with TST, MDZ was found to correlate better with the content of CYP3A4/5 (no correlation vs 0.431) and CYP3A5 (no correlation vs 0.447), and huge variations in enzyme content existed among different genotypes, which explained the lower degree of correlation at the microsomal level. In addition, different genotypes had varying effects on activity at the enzyme level, whereas the difference between activity at the enzyme level probed with TST and that probed with MDZ was not obvious ( P > 0.05), indicating that the effect of gene polymorphisms on correlation between activity probed with these two substrates was limited at the enzyme level. In conclusion, our study demonstrates a high degree of correlation between CYP3A4/5 activity probed with TST and MDZ at the enzyme level but not at the microsomal level and allows us to correctly understand the influence of gene polymorphisms on the correlations.