{"title":"Arsenite-Induced Drug-Drug Interactions in Rats.","authors":"Jingyu Zhang, Weiwei Li, Ying Liu, Yan He, Zihao Cheng, Ximei Li, Yu Chen, Aihua Zhang, Ying Peng, Jiang Zheng","doi":"10.1124/dmd.124.001772","DOIUrl":"10.1124/dmd.124.001772","url":null,"abstract":"<p><p>Arsenite is an important heavy metal. Some Chinese traditional medicines contain significant amounts of arsenite. The aim of this study was to investigate subacute exposure of arsenite on activities of cytochrome P450 enzymes and pharmacokinetic behaviors of drugs in rats. Midazolam, tolbutamide, metoprolol, omeprazole, caffeine, and chlorzoxazone, the probe substrates for cytochrome P450 (CYP) s3A, 2C6, 2D, 2C11, 1A, and 2E, were selected as probe drugs for the pharmacokinetic study. Significant decreases in areas under the curves of probe substrates were observed in rats after consecutive 30-day exposure to As at 12 mg/kg. Microsomal incubation study showed that the subacute exposure to arsenite resulted in little change in effects on the activities of P450 enzymes examined. However, everted gut sac study demonstrated that such exposure induced significant decreases in intestinal absorption of these drugs by both passive diffusion and carrier-mediated transport. In addition, in vivo study showed that the arsenite exposure decreased the rate of peristaltic propulsion. The decreases in intestinal permeability of the probe drugs and peristaltic propulsion rate most likely resulted in the observed decreases in the internal exposure of the probe drugs. Exposure to arsenite may lead to the reduction of the efficiencies of pharmaceutical agents coadministered resulting from the observed drug-drug interactions. SIGNIFICANCE STATEMENT: Exposure to arsenite may lead to the reduction of the efficiencies of pharmaceutical agents coadministered resulting from the observed drug-drug interactions. The present study, we found that P450 enzyme probe drug exposure was reduced in arsenic-exposed animals (areas under the curve) and the intestinal absorption of the drug was reduced in the animals. Subacute arsenic exposure tends to cause damage to intestinal function, which leads to reduced drug absorption.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":" ","pages":"911-918"},"PeriodicalIF":4.4,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141287876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Evaluation and Optimization of a Microcavity Plate-Based Human Hepatocyte Spheroid Model for Predicting Clearance of Slowly Metabolized Drug Candidates.","authors":"David A Kukla, David G Belair, David M Stresser","doi":"10.1124/dmd.124.001653","DOIUrl":"10.1124/dmd.124.001653","url":null,"abstract":"<p><p>In vitro clearance assays are routinely conducted in drug discovery to predict in vivo clearance, but low metabolic turnover compounds are often difficult to evaluate. Hepatocyte spheroids can be cultured for days, achieving higher drug turnover, but have been hindered by limitations on cell number per well. Corning Elplasia microcavity 96-well microplates enable the culture of 79 hepatocyte spheroids per well. In this study, microcavity spheroid properties (size, hepatocyte function, longevity, culturing techniques) were assessed and optimized for clearance assays, which were then compared with microsomes, hepatocyte suspensions, two-dimensional-plated hepatocytes, and macrowell spheroids cultured as one per well. Higher enzyme activity coupled with greater hepatocyte concentrations in microcavity spheroids enabled measurable turnover of all 17 test compounds, unlike the other models that exhibited less drug turnover. Microcavity spheroids also predicted intrinsic clearance (CL<sub>int</sub>) and blood clearance (CL<sub>b</sub>) within threefold for 53% [9/17; average absolute fold error (AAFE), 3.9] and 82% (14/17; AAFE, 2.6) of compounds using a linear regression correction model, respectively. An alternate method incorporating mechanistic modeling that accounts for mass transport (permeability and diffusion) within spheroids demonstrated improved predictivity for CL<sub>int</sub> (12/17; AAFE, 4.0) and CL<sub>b</sub> (14/17; AAFE, 2.1) without the need for empirical scaling factors. The estimated fraction of drug metabolized by cytochrome P450 3A4 (fm,CYP3A4) using 3 μM itraconazole was within 25% of observed values for 6 of 8 compounds, with 5 of 8 compounds within 10%. In sum, spheroid cultures in microcavity plates permit the ability to test and predict clearance as well as fm,CYP3A4 of low metabolic turnover compounds and represent a valuable complement to conventional in vitro clearance assays. SIGNIFICANCE STATEMENT: Culturing multiple spheroids in ultralow attachment microcavities permits accurate quantitation of metabolically stable compounds in substrate depletion assays, overcoming limitations with singly cultured spheroids. In turn, this permits robust estimates of intrinsic clearance, which is improved with the consideration of mass transport within the spheroid. Incubations with 3 μM itraconazole enabled assessments of CYP3A4 involvement in hepatic clearance.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":" ","pages":"797-812"},"PeriodicalIF":4.4,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141081065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hyunwoo Lee, Xiaotong Yang, Pei-Ru Jin, Kyoung-Jae Won, Chang H Kim, Hyunyoung Jeong
{"title":"The Discovery of Gut Microbial Metabolites as Modulators of Host Susceptibility to Acetaminophen-Induced Hepatotoxicity.","authors":"Hyunwoo Lee, Xiaotong Yang, Pei-Ru Jin, Kyoung-Jae Won, Chang H Kim, Hyunyoung Jeong","doi":"10.1124/dmd.123.001541","DOIUrl":"10.1124/dmd.123.001541","url":null,"abstract":"<p><p>The mammalian gut microbiota plays diverse and essential roles in modulating host physiology. Key mediators determining the outcome of the microbiota-host interactions are the small molecule metabolites produced by the gut microbiota. The liver is a major organ exposed to gut microbial metabolites, and it serves as the nexus for maintaining healthy interactions between the gut microbiota and the host. At the same time, the liver is the primary target of potentially harmful gut microbial metabolites. In this review, we provide an up-to-date list of gut microbial metabolites that have been identified to either increase or decrease host susceptibility to acetaminophen (APAP)-induced liver injury. The signaling pathways and molecular factors involved in the progression of APAP-induced hepatotoxicity are well-established, and we propose that the mouse model of APAP-induced hepatotoxicity serves as a model system for uncovering gut microbial metabolites with previously unknown functions. Furthermore, we envision that gut microbial metabolites identified to alter APAP-induced hepatotoxicity likely have broader implications in other liver diseases. SIGNIFICANCE STATEMENT: This review provides an overview of the role of the gut microbiota in modulating the host susceptibility to acetaminophen (APAP)-induced liver injury. It focuses on the roles of gut bacterial small molecule metabolites as mediators of the interaction between the gut microbiota and the liver. It also illustrates the utility of APAP-induced liver injury as a model to identify gut microbial metabolites with biological function.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":" ","pages":"754-764"},"PeriodicalIF":4.4,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11257691/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139671494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Acetaminophen-Induced Hepatic Necrosis: A Reminiscence.","authors":"David Jollow","doi":"10.1124/dmd.123.001278","DOIUrl":"10.1124/dmd.123.001278","url":null,"abstract":"<p><p>In the early 1970s, Dr. B. B. Brodie, head of the Laboratory of Chemical Pharmacology, National Heart Institute, National Institutes of Health, initiated a program to elucidate the mechanism of hepatic necrosis induced in rats by bromobenzene. These studies showed a crucial role for its 3,4-epoxide intermediate, known in part, to collapse to 4-bromophenol. To examine a possible contribution of this phenol to tissue toxicity, some rats were coadministered a high dose of acetaminophen to suppress phenolic clearance by glucuronidation and sulfation. Subsequent examination of liver slices showed that the acetaminophen-only control rats had extensive centrilobular liver necrosis. This article is a personal reminiscence of the events that led up to this accidental observation, how it happened, and the subsequent resolution of the underlying mechanism, including the covalent binding of NAPQI to liver protein as the initial \"hit,\" the glutathione protective threshold, the antidotal activity of cysteine, and the existence of the \"therapeutic window\" for antidotal therapy. Collectively, these studies formed the basis for antidotal therapy of acetaminophen overdose patients. SIGNIFICANCE STATEMENT: Studies in the early 1970s extended Dr. B. Brodie's \"Reactive Metabolites as a Cause of Tissue Injury\" concept to explain the initial events leading to fulminant hepatic necrosis seen after overdoses of acetaminophen. This article, written by one of the key contributors, is a reminiscence of how the studies originated, how they were developed, and their significance for therapy.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":" ","pages":"707-711"},"PeriodicalIF":4.4,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41106025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Quinuclidine <i>N</i>-Oxygenation Mediated by Flavin-Containing Monooxygenases 1 and 3 in Kidney and Liver Microsomes from Humans, Monkeys, Dogs, and Pigs.","authors":"Makiko Shimizu, Miaki Makiguchi, Yasuhiro Uno, Hiroshi Yamazaki","doi":"10.1124/dmd.124.001728","DOIUrl":"10.1124/dmd.124.001728","url":null,"abstract":"<p><p>Flavin-containing monooxygenases (FMOs) are a family of enzymes that are involved in the oxygenation of heteroatom-containing molecules. In humans, FMO3 is the major hepatic form, whereas FMO1 is predominant in the kidneys. FMO1 and FMO3 have also been identified in monkeys, dogs, and pigs. The predicted contribution of human FMO3 to drug candidate <i>N-</i>oxygenation could be estimated using the classic base dissociation constants of the <i>N</i>-containing moiety. A basic quinuclidine moiety was found in natural quinine and medicinal products. Consequently, <i>N</i>-oxygenation of quinuclidine was evaluated using liver and kidney microsomes from humans, monkeys, dogs, and pigs as well as recombinant FMO1, FMO3, and FMO5 enzymes. Experiments using simple reversed-phase liquid chromatography with fluorescence monitoring revealed that recombinant FMO1 mediated quinuclidine <i>N</i>-oxygenation with a high capacity in humans. Moreover, recombinant FMO1, FMO3, and/or FMO5 in monkeys, dogs, and pigs exhibited relatively broad substrate specificity toward quinuclidine <i>N</i>-oxygenation. Kinetic analysis showed that human FMO1 efficiently, and pig FMO1 moderately, mediated quinuclidine <i>N</i>-oxygenation with high capacity, which is consistent with the reported findings for larger substrates readily accepted by pig FMO1 but excluded by human FMO1. In contrast, human FMO3-mediated quinuclidine <i>N</i>-oxygenation was slower than that of the typical FMO3 substrate trimethylamine. These results suggest that some species differences exist in terms of FMO-mediated quinuclidine <i>N-</i>oxygenation in humans and some animal models (monkeys, dogs, and minipigs); however, the potential for quinuclidine, which has a simple chemical structure, to be inhibited clinically by co-administered drugs should be relatively low, especially in human livers. SIGNIFICANCE STATEMENT: The high capacity of human flavin-containing monooxygenase (FMO) 1 to mediate quinuclidine <i>N</i>-oxygenation, a basic moiety in natural products and medicines, was demonstrated by simple reversed-phase liquid chromatography using fluorescence monitoring. The substrate specificity of FMO1 and FMO3 toward quinuclidine <i>N</i>-oxygenation in monkeys, dogs, and pigs was suggested to be relatively broad. Human FMO3-mediated quinuclidine <i>N</i>-oxygenation was slower than trimethylamine <i>N</i>-oxygenation. The likelihood of quinuclidine, with its simple chemical structure, being clinically inhibited by co-administered drugs is relatively low.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":" ","pages":"906-910"},"PeriodicalIF":4.4,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141070523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Martin E Dowty, Ruolun Qiu, Alyssa Dantonio, Mark Niosi, Angela Doran, Amanda Balesano, Stephen W Wright, Gregory S Walker, Raman Sharma
{"title":"The Metabolism and Disposition of Brepocitinib in Humans and Characterization of the Formation Mechanism of an Aminopyridine Metabolite.","authors":"Martin E Dowty, Ruolun Qiu, Alyssa Dantonio, Mark Niosi, Angela Doran, Amanda Balesano, Stephen W Wright, Gregory S Walker, Raman Sharma","doi":"10.1124/dmd.124.001750","DOIUrl":"10.1124/dmd.124.001750","url":null,"abstract":"<p><p>Brepocitinib is an oral once-daily Janus kinase 1 and Tyrosine kinase 2 selective inhibitor currently in development for the treatment of several autoimmune disorders. Mass balance and metabolic profiles were determined using accelerator mass spectrometry in six healthy male participants following a single oral 60 mg dose of <sup>14</sup>C-brepocitinib (∼300 nCi). The average mass balance recovery was 96.7% ± 6.3%, with the majority of dose (88.0% ± 8.0%) recovered in urine and 8.7% ± 2.1% of the dose recovered in feces. Absorption of brepocitinib was rapid, with maximal plasma concentrations of total radioactivity and brepocitinib achieved within 0.5 hours after dosing. Circulating radioactivity consisted primarily of brepocitinib (47.8%) and metabolite M1 (37.1%) derived from hydroxylation at the C5' position of the pyrazole ring. Fractional contributions to metabolism via cytochrome P450 enzymes were determined to be 0.77 for CYP3A4/5 and 0.14 for CYP1A2 based on phenotyping studies in human liver microsomes. However, additional clinical studies are required to understand the potential contribution of CYP1A1. Approximately 83% of the dose was eliminated as N-methylpyrazolyl oxidative metabolites, with 52.1% of the dose excreted as M1 alone. Notably, M1 was not observed as a circulating metabolite in earlier metabolic profiling of human plasma from a multiple ascending dose study with unlabeled brepocitinib. Mechanistic studies revealed that M1 was highly unstable in human plasma and phosphate buffer, undergoing chemical oxidation leading to loss of the 5-hydroxy-1-methylpyrazole moiety and formation of aminopyrimidine cleavage product M2. Time-dependent inhibition and trapping studies with M1 yielded insights into the mechanism of this unusual and unexpected instability. SIGNIFICANCE STATEMENT: This study provides a detailed understanding of the disposition and metabolism of brepocitinib, a JAK1/TYK2 inhibitor for atopic dermatitis, in humans as well as characterization of clearance pathways and pharmacokinetics of brepocitinib and its metabolites.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":" ","pages":"690-702"},"PeriodicalIF":3.9,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140891068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Correction to \"Quantitative Analysis of mRNA and Protein Expression Levels of Aldo-Keto Reductase and Short-Chain Dehydrogenase/Reductase Isoforms in the Human Intestine\".","authors":"","doi":"10.1124/dmd.123.001402err","DOIUrl":"https://doi.org/10.1124/dmd.123.001402err","url":null,"abstract":"","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":"52 7","pages":"703"},"PeriodicalIF":3.9,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141418323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Application of Electro-Activated Dissociation Fragmentation Technique to Identifying Glucuronidation and Oxidative Metabolism Sites of Vepdegestrant by Liquid Chromatography-High Resolution Mass Spectrometry.","authors":"Yifei He, Pengyi Hou, Zhimin Long, Yuandong Zheng, Chongzhuang Tang, Elliott Jones, Xingxing Diao, Mingshe Zhu","doi":"10.1124/dmd.124.001661","DOIUrl":"10.1124/dmd.124.001661","url":null,"abstract":"<p><p>Drug metabolite identification is an integrated part of drug metabolism and pharmacokinetics studies in drug discovery and development. Definitive identification of metabolic modification sides of test compounds such as screening metabolic soft spots and supporting metabolite synthesis are often required. Currently, liquid chromatography-high resolution mass spectrometry is the dominant analytical platform for metabolite identification. However, the interpretation of product ion spectra generated by commonly used collision-induced disassociation (CID) and higher-energy collisional dissociation (HCD) often fails to identify locations of metabolic modifications, especially glucuronidation. Recently, a ZenoTOF 7600 mass spectrometer equipped with electron-activated dissociation (EAD-HRMS) was introduced. The primary objective of this study was to apply EAD-HRMS to identify metabolism sites of vepdegestrant (ARV-471), a model compound that consists of multiple functional groups. ARV-471 was incubated in dog liver microsomes and 12 phase I metabolites and glucuronides were detected. EAD generated unique product ions via orthogonal fragmentation, which allowed for accurately determining the metabolism sites of ARV-471, including phenol glucuronidation, piperazine <i>N</i>-dealkylation, glutarimide hydrolysis, piperidine oxidation, and piperidine lactam formation. In contrast, CID and HCD spectral interpretation failed to identify modification sites of three <i>O</i>-glucuronides and three phase I metabolites. The results demonstrated that EAD has significant advantages over CID and HCD in definitive structural elucidation of glucuronides and phase I metabolites although the utility of EAD-HRMS in identifying various types of drug metabolites remains to be further evaluated. SIGNIFICANCE STATEMENT: Definitive identification of metabolic modification sites by liquid chromatography-high resolution mass spectrometry is highly needed in drug metabolism research, such as screening metabolic soft spots and supporting metabolite synthesis. However, commonly used collision-induced dissociation (CID) and higher-energy collisional dissociation (HCD) fragmentation techniques often fail to provide critical information for definitive structural elucidation. In this study, the electron-activated dissociation (EAD) was applied to identifying glucuronidation and oxidative metabolism sites of vepdegestrant, which generated significantly better results than CID and HCD.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":" ","pages":"634-643"},"PeriodicalIF":3.9,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141236299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Pharmacokinetic/Pharmacodynamic Assessment of the Structural Refinement of Clopidogrel Focusing on the Balance between Bioactivation and Deactivation.","authors":"Dong Sun, Yingze Liu, Lin Zhu, Zhiping Xu, Yuyao Zhang, Haipeng Li, Huan Yang, Xia Cao, Jingkai Gu","doi":"10.1124/dmd.124.001699","DOIUrl":"10.1124/dmd.124.001699","url":null,"abstract":"<p><p>The delicate balance between ischemic and bleeding risks is a critical factor in antiplatelet therapy administration. Clopidogrel and prasugrel, belonging to the thienopyridine class of antiplatelet drugs, are known for their variability in individual responsiveness and high incidence of bleeding events, respectively. The present study is centered on the development and assessment of a range of deuterated thienopyridine derivatives, leveraging insights from structure-pharmacokinetic relationships of clopidogrel and prasugrel. Our approaches were grounded in the molecular framework of clopidogrel and incorporated the C<sub>2</sub>-pharmacophore design from prasugrel. The selection of ester or carbamate substituents at the C<sub>2</sub>-position facilitated the generation of the 2-oxointermediate through hydrolysis, akin to prasugrel, thereby bypassing the issue of CYP2C19 dependency. The bulky C<sub>2</sub>-pharmacophore in our approach distinguishes itself from prasugrel's acetyloxy substituent by exhibiting a moderated hydrolysis rate, resulting in a more gradual formation of the active metabolite. Excessive and rapid release of the active metabolite, believed to be linked with an elevated risk of bleeding, is thus mitigated. Our proposed structural modification retains the hydrolysis-sensitive methyl ester of clopidogrel but substitutes it with a deuterated methyl group, shown to effectively reduce metabolic deactivation. Three promising compounds demonstrated a pharmacokinetic profile similar to that of clopidogrel at four times the dose, while also augmenting its antiplatelet activity. SIGNIFICANCE STATEMENT: Inspired by the structure-pharmacokinetic relationship of clopidogrel and prasugrel, a range of clopidogrel derivatives were designed, synthesized, and assessed. Among them, three promising compounds have been identified, striking a delicate balance between efficacy and safety for antiplatelet therapy. Additionally, the ozagrel prodrug conjugate was discovered to exert a synergistic therapeutic effect alongside clopidogrel.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":" ","pages":"654-661"},"PeriodicalIF":3.9,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140903851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tissue-, Region-, and Gene-Specific Induction of Microsomal Epoxide Hydrolase Expression and Activity in the Mouse Intestine by Arsenic in Drinking Water.","authors":"Hui Li, Xiaoyu Fan, Xinxin Ding, Qing-Yu Zhang","doi":"10.1124/dmd.124.001720","DOIUrl":"10.1124/dmd.124.001720","url":null,"abstract":"<p><p>This study aimed to characterize the effects of arsenic exposure on the expression of microsomal epoxide hydrolase (mEH or EPHX1) and soluble epoxide hydrolase (sEH or EPHX2) in the liver and small intestine. C57BL/6 mice were exposed to sodium arsenite in drinking water at various doses for up to 28 days. Intestinal, but not hepatic, mEH mRNA and protein expression was induced by arsenic at 25 ppm, in both males and females, whereas hepatic mEH expression was induced by arsenic at 50 or 100 ppm. The induction of mEH was gene specific, as the arsenic exposure did not induce sEH expression in either tissue. Within the small intestine, mEH expression was induced only in the proximal, but not the distal segments. The induction of intestinal mEH was accompanied by increases in microsomal enzymatic activities toward a model mEH substrate, <i>cis</i>-stilbene oxide, and an epoxide-containing drug, oprozomib, in vitro, and by increases in the levels of PR-176, the main hydrolysis metabolite of oprozomib, in the proximal small intestine of oprozomib-treated mice. These findings suggest that intestinal mEH, playing a major role in converting xenobiotic epoxides to less reactive diols, but not sEH, preferring endogenous epoxides as substrates, is relevant to the adverse effects of arsenic exposure, and that further studies of the interactions between drinking water arsenic exposure and the disposition or possible adverse effects of epoxide-containing drugs and other xenobiotic compounds in the intestine are warranted. SIGNIFICANCE STATEMENT: Consumption of arsenic-contaminated water has been associated with increased risks of various adverse health effects, such as diabetes, in humans. The small intestinal epithelial cells are the main site of absorption of ingested arsenic, but they are not well characterized for arsenic exposure-related changes. This study identified gene expression changes in the small intestine that may be mechanistically linked to the adverse effects of arsenic exposure and possible interactions between arsenic ingestion and the pharmacokinetics of epoxide-containing drugs in vivo.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":" ","pages":"681-689"},"PeriodicalIF":4.4,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11185820/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140891103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}