人类药物的残留物在地表水中被广泛检测到,可以被水生生物吸收和生物积累,尤其是鱼。评估可电离有机化合物生物累积潜力的关键挑战之一,比如药物,缺乏生物转化的经验数据。在本研究中,我们评估了12种药物的体外内在清除率(CLINT),单独和另一些作为混合物,在虹鳟鱼(Oncorhynchusmykiss)肝脏S9部分(RT-S9)中,符合OECD测试指南319B。测试物质包括四种抗炎剂(双氯芬酸,布洛芬,酮洛芬,萘普生),七种抗抑郁药/抗精神病药(西酞普兰,氟哌啶醇,左甲丙嗪,米氮平,利培酮,舍曲林,文拉法辛)和文拉法辛的O-去甲基代谢物。检测到双氯芬酸的可量化内在间隙,布洛芬,萘普生,左甲丙嗪,还有舍曲林.除了双氯芬酸,其他四种药物的体外清除率被证明严重依赖于细胞色素P450(CYP)代谢.因此,我们还确定了相同的十二种药物对CYP1A样(7-乙氧基间苯二酚-O-去乙基化,EROD)和CYP3A样(苄氧基-4-三氟甲基香豆素-O-去苄氧基化,BFCOD)在RT-S9中的活性,使用IC50位移测定法。因此,左甲丙嗪和舍曲林被确定为EROD和BFCOD活性的最有效抑制剂(未结合的IC50<10µM),其次是西酞普兰和氟哌啶醇(10µM
Residues of human pharmaceuticals are widely detected in surface waters and can be taken up by and bioaccumulate in aquatic organisms, especially fish. One of the key challenges in assessing the bioaccumulation potential of ionizable organic compounds, such as the pharmaceuticals, is the lack of empirical data for biotransformation. In the present study, we assessed the in vitro intrinsic clearances (CLINT) of twelve pharmaceuticals, individually and some additionally as mixtures, in rainbow trout (Oncorhynchus mykiss) liver S9 fractions (RT-S9) adhering to the OECD test guidance 319B. The test substances included four anti-inflammatory agents (diclofenac, ibuprofen, ketoprofen, naproxen), seven antidepressants/antipsychotics (citalopram, haloperidol, levomepromazine, mirtazapine, risperidone, sertraline, venlafaxine) and the O-desmethyl metabolite of venlafaxine. Quantifiable intrinsic clearances were detected for diclofenac, ibuprofen, naproxen, levomepromazine, and sertraline. Apart from diclofenac, the in vitro clearances of the other four pharmaceuticals were shown to be critically dependent on the cytochrome P450 (CYP) metabolism. Therefore, we also determined the half-maximal inhibitory concentrations (IC50) of the same twelve pharmaceuticals toward CYP1A-like (7-ethoxyresorufin-O-deethylation, EROD) and CYP3A-like (benzyloxy-4-trifluoromethylcoumarin-O-debenzyloxylation, BFCOD) activities in RT-S9 using IC50 shift assay. As a result, levomepromazine and sertraline were identified as the most potent inhibitors of both EROD and BFCOD activity (unbound IC50 < 10 µM each), followed by citalopram and haloperidol (10 µM < IC50 < 100 µM). Additionally, mirtazapine was a selective EROD inhibitor (IC50 ∼ 30 µM). The inhibitory impacts of haloperidol and sertraline were indicatively time dependent. Finally, we carried out intrinsic clearance assays with mixtures of diclofenac, ibuprofen, naproxen, levomepromazine, and sertraline to examine the impacts of EROD and BFCOD inhibitions on their in vitro CLINT in RT-S9. Our in vitro data suggests that the intrinsic clearances of ibuprofen, levomepromazine, and sertraline in rainbow trout can be significantly reduced as the result of P450 inhibition by pharmaceutical mixtures, whereas the clearances of diclofenac and naproxen are less impacted.