Potent and Specific Inhibition of mMate1-Mediated Efflux of Type I Organic Cations in the Liver and Kidney by Pyrimethamine
Potent and Specific Inhibition of mMate1-Mediated Efflux of Type I Organic Cations in the Liver and Kidney by Pyrimethamine
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DOI：
10.1124/jpet.109.163642
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发表时间：
2010-04-01
影响因子：
3.5
通讯作者：
Sugiyama, Yuichi
中科院分区：
文献类型：
--
作者：
Ito, Sumito;Kusuhara, Hiroyuki;Sugiyama, Yuichi
这份报告描述了一种有效和选择性的多药和毒素排泄(Mate)蛋白的抑制剂，乙胺胺(PYR)，并检测了它对小鼠典型Mate1底物的尿液和胆汁排泄的影响。体外抑制研究表明，在肾脏有机阳离子转运体mOctn1和mOctn2(Ki和gt；30mU)、mOct1(K-I=3.6mM)和mOct2(K-I=6.0mM)中，PYR对小鼠(M)Mate1(K-I=145 nM)具有有效的抑制作用。在H+向外梯度存在的情况下，PYR抑制肾刷状缘膜小泡(K-I=41 nM)和小管膜泡摄取二甲双胍。PYR治疗显著增加了小鼠四乙基铵的肾/血浆比，以及二甲双胍的肝/肾/血浆比，但不影响它们的血药浓度和尿排泄率。此外，作为二甲双胍抑制糖异生的生物标志物，PYR治疗组的血浆乳酸浓度显著高于对照组。这些结果不仅表明mMate1在有机阳离子进入小鼠尿液和胆汁的外流中的重要性，而且也表明Mate蛋白介导的小管外排在二甲双胍治疗效果中的重要性。在H+向外梯度存在的情况下，PYR对人(H)MATE_1和hMATE_2-K(K-I分别为77和46 nM)和人肾BBMV(K-I=31 nM)中的H~+和有机阳离子交换器都有很强的抑制作用。综上所述，PYR可以作为一种有效的人类配偶转运蛋白的探针抑制剂。
This report describes a potent and selective inhibitor of multidrug and toxin extrusion (MATE) protein, pyrimethamine (PYR), and examines its effect on the urinary and biliary excretion of typical Mate1 substrates in mice. In vitro inhibition studies demonstrated that PYR is a potent inhibitor of mouse (m) Mate1 (K-i = 145 nM) among renal organic cation transporters mOctn1 and mOctn2 (K-i > 30 mu M), mOct1 (K-i = 3.6 mu M), and mOct2 (K-i = 6.0 mu M). PYR inhibited the uptake of metformin by kidney brush-border membrane vesicles (BBMVs) (K-i = 41 nM) and canalicular membrane vesicles in the presence of outward gradient of H+. PYR treatment significantly increased the kidney-to-plasma ratio of tetraethylammonium, and both the liver-and kidney-to-plasma ratios of metformin in mice, whereas it did not affect their plasma concentrations and urinary excretion rates. Furthermore, the plasma lactate concentration, a biomarker for inhibition of gluconeogenesis by metformin, was significantly higher in the PYR-treated group than in the control group. These results not only suggest the importance of mMate1 in the efflux of organic cations into the urine and bile in mice but also the importance of canalicular efflux mediated by MATE proteins for the therapeutic efficacy of metformin. PYR is a potent inhibitor of human (h)MATE1 and hMATE2-K (K-i = 77 and 46 nM, respectively) and H+ and organic cation exchanger in human kidney BBMVs ( K-i = 31 nM) in the presence of outward gradient of H+. Taken together, PYR can be used as a potent probe inhibitor of human MATE transporters.