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Mit C, Bado-Nilles A, Daniele G, Giroud B, Vulliet E, Beaudouin R. The toxicokinetics of bisphenol A and its metabolites in fish elucidated by a PBTK model. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2022; 247:106174. [PMID: 35462154 DOI: 10.1016/j.aquatox.2022.106174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 04/14/2022] [Accepted: 04/15/2022] [Indexed: 06/14/2023]
Abstract
Bisphenol A (BPA) is a chemical of major concern due to its endocrine disrupting function, high production volume, and persistence in the aquatic environment. Consequently, organisms such as fish are subject to chronic exposure to BPA. However, physiologically-based toxicokinetic (PBTK) models, which are valuable tools to improve the understanding of a chemical's fate in an organism, have never been specifically adapted to model BPA toxicokinetics (TK) in fish. In our work, an existing PBTK developed for four different fish species was modified to model BPA ADME processes (absorption, distribution, metabolization and excretion). The metabolization of BPA into BPA-monoglucuronide (BPA gluc) and BPA-monosulfate (BPA sulf) and their TK in various organs was taking into account in the model. Experiments were performed to generate BPA TK data in a model species commonly used in ecotoxicology, the stickleback. The model structure had to include two sites of metabolization to simulate BPA TK accurately in stickleback organs. Thus, the fish liver may not be the only site of the metabolization of BPA: plasma or gills could also play a role in BPA metabolization. The PBTK model predictive performance evaluated on literature data in zebrafish and rainbow trout concurs with this conclusion. Finally, a calibration mixing data from the three species was compared to the calibration on stickleback data only.
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Affiliation(s)
- Corentin Mit
- Experimental Toxicology and Modeling Unit, INERIS, UMR-I 02 SEBIO, Verneuil en Halatte 65550, France; Ecotoxicology of Substances and Fields Unit, INERIS, UMR-I 02 SEBIO, Verneuil en Halatte 65550, France
| | - Anne Bado-Nilles
- Ecotoxicology of Substances and Fields Unit, INERIS, UMR-I 02 SEBIO, Verneuil en Halatte 65550, France
| | - Gaëlle Daniele
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1, Institut des Sciences Analytiques, UMR 5280, 5 rue de la Doua, Villeurbanne F-69100, France
| | - Barbara Giroud
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1, Institut des Sciences Analytiques, UMR 5280, 5 rue de la Doua, Villeurbanne F-69100, France
| | - Emmanuelle Vulliet
- Univ Lyon, CNRS, Université Claude Bernard Lyon 1, Institut des Sciences Analytiques, UMR 5280, 5 rue de la Doua, Villeurbanne F-69100, France
| | - Rémy Beaudouin
- Experimental Toxicology and Modeling Unit, INERIS, UMR-I 02 SEBIO, Verneuil en Halatte 65550, France.
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2
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Gingrich J, Filipovic D, Conolly R, Bhattacharya S, Veiga-Lopez A. Pregnancy-specific physiologically-based toxicokinetic models for bisphenol A and bisphenol S. ENVIRONMENT INTERNATIONAL 2021; 147:106301. [PMID: 33360411 PMCID: PMC7856209 DOI: 10.1016/j.envint.2020.106301] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 11/12/2020] [Accepted: 11/21/2020] [Indexed: 06/12/2023]
Abstract
Predictions from physiologically based toxicokinetic (PBTK) models can help inform human health risk assessment for potentially toxic chemicals in the environment. Bisphenol S (BPS) is the second most abundant bisphenol detected in humans in the United States, after bisphenol A (BPA). We have recently demonstrated that BPS, much like BPA, can cross the placental barrier and disrupt placental function. Differences in physicochemical properties, toxicokinetics, and exposure outcomes between BPA and other bisphenols prevent direct extrapolation of existing BPA PBTK models to BPS. The current study aimed to develop pregnancy-specific PBTK (p-PBTK) models for BPA and BPS, using a common p-PBTK model structure. Novel paired maternal and fetal pregnancy data sets for total, unconjugated, and conjugated BPA and BPS plasma concentrations from three independent studies in pregnant sheep were used for model calibration. The nine-compartment (maternal blood, liver, kidney, fat, placenta and rest of body, and fetal liver, blood and rest of body) models simulated maternal and fetal experimental data for both BPA and BPS within one standard deviation for the majority of the experimental data points, highlighting the robustness of both models. Simulations were run to examine fetal exposure following daily maternal exposure to BPA or BPS at their tolerable daily intake dose over a two-week period. These predictive simulations show fetal accumulation of both bisphenols over time. Interestingly, the steady-state approximation following this dosing strategy achieved a fetal concentration of unconjugated BPA to levels observed in cord blood from human biomonitoring studies. These models advance our understanding of bisphenolic compound toxicokinetics during pregnancy and may be used as a quantitative comparison tool in future p-PBTK models for related chemicals.
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Affiliation(s)
- Jeremy Gingrich
- Department of Pharmacology and Toxicology, College of Natural Sciences, Michigan State University, East Lansing, MI 48824, USA
| | - David Filipovic
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI 48824, USA; Department of Computational Mathematics, Science and Engineering, Michigan State University, East Lansing, MI 48824, USA; Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI 48824, USA
| | - Rory Conolly
- Institute for Integrative Toxicology, Michigan State University, East Lansing, MI 48824, USA
| | - Sudin Bhattacharya
- Department of Pharmacology and Toxicology, College of Natural Sciences, Michigan State University, East Lansing, MI 48824, USA; Department of Biomedical Engineering, Michigan State University, East Lansing, MI 48824, USA; Institute for Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI 48824, USA; Center for Research on Ingredient Safety, Michigan State University, East Lansing, MI 48824, USA; Institute for Integrative Toxicology, Michigan State University, East Lansing, MI 48824, USA
| | - Almudena Veiga-Lopez
- Department of Pathology, University of Illinois at Chicago, Chicago, IL 60612, USA; The ChicAgo Center for Health and Environment, University of Illinois at Chicago, Chicago, IL 60612, USA.
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3
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Gray LE, Furr JR, Conley JM, Lambright CS, Evans N, Cardon MC, Wilson VS, Foster PM, Hartig PC. A Conflicted Tale of Two Novel AR Antagonists In Vitro and In Vivo: Pyrifluquinazon Versus Bisphenol C. Toxicol Sci 2020; 168:632-643. [PMID: 30649549 DOI: 10.1093/toxsci/kfz010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Chemicals that disrupt androgen receptor (AR) function in utero induce a cascade of adverse effects in male rats including reduced anogenital distance, retained nipples, and reproductive tract malformations. The objective of this study was to compare the in vitro and in utero activities of two novel AR antagonists, bisphenol C (BPC) and pyrifluquinazon (PFQ). In vitro, BPC was as potent an AR antagonist as hydroxyflutamide. Furthermore, BPC inhibited fetal testis testosterone production and testis gene expression ex vivo. However, when BPC was administered at 100 and 200 mg/kg/d in utero, the reproductive tract of the male offspring was minimally affected. None of the males displayed reproductive malformations. For comparison, in utero administration of flutamide has been shown to induce malformations in 100% of males at 6 mg/kg/d. In vitro, PFQ was several orders of magnitude less potent than BPC, vinclozolin, or procymidone. However, in utero administration of 12.5, 25, 50, and 100 mg PFQ/kg/d on GD 14-18 induced antiandrogenic effects at all dosage levels and 91% of the males displayed reproductive malformation in the high dose group. Overall, BPC was ∼380-fold more potent than PFQ in vitro, whereas PFQ was far more potent than BPC in utero. Incorporating toxicokinetic and toxicodynamic data into in vitro to in vivo extrapolations would reduce the discordance between the in vitro and in utero effects of PFQ and BPC and combining in vitro results with a short-term Hershberger assay would reduce the uncertainty in predicting the in utero effects of antiandrogenic chemicals.
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Affiliation(s)
- Leon Earl Gray
- Reproductive Toxicology Branch, Toxicology Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency (U.S. EPA), Research Triangle Park, North Carolina 27711
| | | | - Justin M Conley
- Reproductive Toxicology Branch, Toxicology Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency (U.S. EPA), Research Triangle Park, North Carolina 27711
| | - Christy S Lambright
- Reproductive Toxicology Branch, Toxicology Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency (U.S. EPA), Research Triangle Park, North Carolina 27711
| | - Nicola Evans
- Reproductive Toxicology Branch, Toxicology Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency (U.S. EPA), Research Triangle Park, North Carolina 27711
| | - Mary C Cardon
- Reproductive Toxicology Branch, Toxicology Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency (U.S. EPA), Research Triangle Park, North Carolina 27711
| | - Vickie S Wilson
- Reproductive Toxicology Branch, Toxicology Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency (U.S. EPA), Research Triangle Park, North Carolina 27711
| | | | - Phillip C Hartig
- Reproductive Toxicology Branch, Toxicology Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency (U.S. EPA), Research Triangle Park, North Carolina 27711
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Codaccioni M, Bois F, Brochot C. Placental transfer of xenobiotics in pregnancy physiologically-based pharmacokinetic models: Structure and data. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.comtox.2019.100111] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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5
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Grandin FC, Lacroix MZ, Gayrard V, Gauderat G, Mila H, Toutain PL, Picard-Hagen N. Bisphenol S instead of Bisphenol A: Toxicokinetic investigations in the ovine materno-feto-placental unit. ENVIRONMENT INTERNATIONAL 2018; 120:584-592. [PMID: 30212803 DOI: 10.1016/j.envint.2018.08.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 08/03/2018] [Accepted: 08/07/2018] [Indexed: 06/08/2023]
Abstract
Bisphenol S (BPS) is widely used as a substitute for Bisphenol A in consumer products. Despite its potential endocrine-disrupting effects and widespread exposure, toxicokinetic data, particularly during the critical period of pregnancy, are not available for BPS. The objectives of our study were to evaluate the mechanisms determining fetal exposure to BPS and to BPS glucuronide (BPSG) and to compare them with those prevailing for BPA. The disposition of BPS and BPSG was evaluated in the materno-fetal unit of the catheterized pregnant ewe model, following intravenous administrations of BPS and BPSG to mothers and their fetuses. In a second experiment, the rate of BPS accumulation in the fetal compartment was determined under steady-state conditions after repeated intravenous BPS administrations to the mother. In the maternal compartment, BPS was mainly metabolized into BPSG and totally eliminated in urine. Only 0.40% of the maternal dose was transferred to the fetus. However, once in the fetal compartment, 26% of the fetal dose was rapidly eliminated through placental transfer, while 46% of BPS was metabolized into BPSG which remained trapped in the fetal compartment. Thus, the elimination of BPSG from the fetal compartment required its back-conversion into bioactive BPS, leading to an 87% enhancement of the fetal BPS exposure. Our findings demonstrate that, despite the low materno-fetal placental transfer of BPS, this substitute for BPA is able to accumulate in the fetal compartment after repeated maternal exposure, leading to chronic fetal exposure to BPS in a range of concentrations similar to those of BPA.
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Affiliation(s)
- Flore C Grandin
- Toxalim, INRA (Institut National de la Recherche Agronomique), Université de Toulouse, ENVT (Ecole Nationale Vétérinaire de Toulouse), EIP (Ecole d'Ingénieurs de Purpan), UPS (Université Paul Sabatier), Toulouse, France.
| | | | - Véronique Gayrard
- Toxalim, INRA (Institut National de la Recherche Agronomique), Université de Toulouse, ENVT (Ecole Nationale Vétérinaire de Toulouse), EIP (Ecole d'Ingénieurs de Purpan), UPS (Université Paul Sabatier), Toulouse, France.
| | - Glenn Gauderat
- Toxalim, INRA (Institut National de la Recherche Agronomique), Université de Toulouse, ENVT (Ecole Nationale Vétérinaire de Toulouse), EIP (Ecole d'Ingénieurs de Purpan), UPS (Université Paul Sabatier), Toulouse, France
| | - Hanna Mila
- Toxalim, INRA (Institut National de la Recherche Agronomique), Université de Toulouse, ENVT (Ecole Nationale Vétérinaire de Toulouse), EIP (Ecole d'Ingénieurs de Purpan), UPS (Université Paul Sabatier), Toulouse, France.
| | | | - Nicole Picard-Hagen
- Toxalim, INRA (Institut National de la Recherche Agronomique), Université de Toulouse, ENVT (Ecole Nationale Vétérinaire de Toulouse), EIP (Ecole d'Ingénieurs de Purpan), UPS (Université Paul Sabatier), Toulouse, France.
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6
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Johnson SA, Spollen WG, Manshack LK, Bivens NJ, Givan SA, Rosenfeld CS. Hypothalamic transcriptomic alterations in male and female California mice ( Peromyscus californicus) developmentally exposed to bisphenol A or ethinyl estradiol. Physiol Rep 2018; 5:5/3/e13133. [PMID: 28196854 PMCID: PMC5309579 DOI: 10.14814/phy2.13133] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 12/15/2016] [Accepted: 12/26/2016] [Indexed: 12/22/2022] Open
Abstract
Bisphenol A (BPA) is an endocrine‐disrupting chemical (EDC) prevalent in many household items. Rodent models and human epidemiological studies have linked this chemical to neurobehavior impairments. In California mice, developmental exposure to BPA results in sociosexual disorders at adulthood, including communication and biparental care deficits, behaviors that are primarily regulated by the hypothalamus. Thus, we sought to examine the transcriptomic profile in this brain region of juvenile male and female California mice offspring exposed from periconception through lactation to BPA or ethinyl estradiol (EE, estrogen present in birth control pills and considered a positive estrogen control for BPA studies). Two weeks prior to breeding, P0 females were fed a control diet, or this diet supplemented with 50 mg BPA/kg feed weight or 0.1 ppb EE, and continued on the diets through lactation. At weaning, brains from male and female offspring were collected, hypothalamic RNA isolated, and RNA‐seq analysis performed. Results indicate that BPA and EE groups clustered separately from controls with BPA and EE exposure leading to unique set of signature gene profiles. Kcnd3 was downregulated in the hypothalamus of BPA‐ and EE‐exposed females, whereas Tbl2, Topors, Kif3a, and Phactr2 were upregulated in these groups. Comparison of transcripts differentially expressed in BPA and EE groups revealed significant enrichment of gene ontology terms associated with microtubule‐based processes. Current results show that perinatal exposure to BPA or EE can result in several transcriptomic alterations, including those associated with microtubule functions, in the hypothalamus of California mice. It remains to be determined whether these genes mediate BPA‐induced behavioral disruptions.
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Affiliation(s)
- Sarah A Johnson
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri.,Biomedical Sciences, University of Missouri, Columbia, Missouri.,Animal Sciences, University of Missouri, Columbia, Missouri
| | - William G Spollen
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri.,Informatics Research Core Facility University of Missouri, Columbia, Missouri
| | - Lindsey K Manshack
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri.,Biomedical Sciences, University of Missouri, Columbia, Missouri
| | - Nathan J Bivens
- DNA Core Facility, University of Missouri, Columbia, Missouri
| | - Scott A Givan
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri .,Informatics Research Core Facility University of Missouri, Columbia, Missouri.,Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri
| | - Cheryl S Rosenfeld
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri .,Biomedical Sciences, University of Missouri, Columbia, Missouri.,Genetics Area Program, University of Missouri, Columbia, Missouri.,Thompson Center for Autism and Neurobehavioral Disorders, University of Missouri, Columbia, Missouri
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7
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Sharma RP, Schuhmacher M, Kumar V. The development of a pregnancy PBPK Model for Bisphenol A and its evaluation with the available biomonitoring data. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 624:55-68. [PMID: 29247905 DOI: 10.1016/j.scitotenv.2017.12.023] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 12/03/2017] [Accepted: 12/03/2017] [Indexed: 05/20/2023]
Abstract
Recent studies suggest universal fetal exposure to Bisphenol A (BPA) and its association with the adverse birth outcomes. Estimation of the fetal plasma BPA concentration from the maternal plasma BPA would be highly useful to predict its associated risk to this specific population. The objective of current work is to develop a pregnancy-physiologically based pharmacokinetic (P-PBPK) model to predict the toxicokinetic profile of BPA in the fetus during gestational growth, and to evaluate the developed model using biomonitoring data obtained from different pregnancy cohort studies. To achieve this objective, first, the adult PBPK model was developed and validated with the human BPA toxicokinetic data. This validated human PBPK model was extended to develop a P-PBPK model, which included the physiological changes during pregnancy and the fetus sub-model. The developed model would be able to predict the BPA pharmacokinetics (PKs) in both mother and fetus. Transplacental BPA kinetics parameters for this study were taken from the previous pregnant mice study. Both oral and dermal exposure routes were included into the model to simulate total BPA internal exposure. The impact of conjugation and deconjugation of the BPA and its metabolites on fetal PKs was investigated. The developed P-PBPK model was evaluated against the observed BPA concentrations in cord blood, fetus liver and amniotic fluid considering maternal blood concentration as an exposure source. A range of maternal exposure dose for the oral and dermal routes was estimated, so that simulation concentration matched the observed highest and lowest mother plasma concentration in different cohorts' studies. The developed model could be used to address the concerns regarding possible adverse health effects in the fetus being exposed to BPA and might be useful in identifying critical windows of exposure during pregnancy.
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Affiliation(s)
- Raju Prasad Sharma
- Center of Environmental Food and Toxicological Technology (TecnATox), Departament d'Enginyeria Química, Universitat Rovira i Virgili, Tarragona, Catalonia, Spain
| | - Marta Schuhmacher
- Center of Environmental Food and Toxicological Technology (TecnATox), Departament d'Enginyeria Química, Universitat Rovira i Virgili, Tarragona, Catalonia, Spain
| | - Vikas Kumar
- Center of Environmental Food and Toxicological Technology (TecnATox), Departament d'Enginyeria Química, Universitat Rovira i Virgili, Tarragona, Catalonia, Spain.
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Oh J, Choi JW, Ahn YA, Kim S. Pharmacokinetics of bisphenol S in humans after single oral administration. ENVIRONMENT INTERNATIONAL 2018; 112:127-133. [PMID: 29272776 DOI: 10.1016/j.envint.2017.11.020] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Revised: 11/13/2017] [Accepted: 11/21/2017] [Indexed: 05/02/2023]
Abstract
Bisphenol S (BPS) has been introduced as a substitute for bisphenol A (BPA), and widely used in the manufacture of polycarbonate plastics, epoxy resins and thermal papers. Despite its adverse health outcomes and widespread exposure, pharmacokinetic data of BPS are not available for either animals or humans. The objective of the study is to describe pharmacokinetic characteristics of BPS in human body after a single oral administration with a compartmental pharmacokinetic model. Seven healthy young adults were orally exposed to 8.75μg/bw of d4-BPS, and serum and urine samples were collected for 48h. The concentrations of total and unconjugated d4-BPS in samples were measured using HPLC-MS/MS. Based on the time-concentration profiles in serum and urine, non-compartmental analysis was performed, and two-compartment model was constructed and validated. As a result of non-compartmental analysis, total d4-BPS was rapidly absorbed within 1h (0.7±0.3h) after oral administration, and excreted in urine with terminal half-life of <7h (6.8±0.7h). Fractional urinary excretion (Fue) of total d4-BPS for 48h was 92±17% (67-104%) for men and 70±36% (59-77%) for women. The two-compartment model well described pharmacokinetic properties of BPS, and its parameter estimates were consistent with those from non-compartmental analysis. This study provides information on absorption, distribution, metabolism and elimination of BPS in human body, and the pharmacokinetic model can be utilized for estimating exposure dose of BPS, contributing to more realistic exposure assessment.
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Affiliation(s)
- Jiwon Oh
- Department of Environmental Health Sciences, School of Public Health, Seoul National University, Seoul 08826, South Korea.
| | - Jeong Weon Choi
- Department of Environmental Health Sciences, School of Public Health, Seoul National University, Seoul 08826, South Korea.
| | - Young-Ah Ahn
- Department of Environmental Health Sciences, School of Public Health, Seoul National University, Seoul 08826, South Korea.
| | - Sungkyoon Kim
- Department of Environmental Health Sciences, School of Public Health, Seoul National University, Seoul 08826, South Korea; Institute of Health and Environment, School of Public Health, Seoul National University, Seoul 08826, South Korea.
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9
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Johnson SA, Javurek AB, Painter MS, Ellersieck MR, Welsh TH, Camacho L, Lewis SM, Vanlandingham MM, Ferguson SA, Rosenfeld CS. Effects of developmental exposure to bisphenol A on spatial navigational learning and memory in rats: A CLARITY-BPA study. Horm Behav 2016; 80:139-148. [PMID: 26436835 PMCID: PMC4818668 DOI: 10.1016/j.yhbeh.2015.09.005] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Revised: 08/22/2015] [Accepted: 09/30/2015] [Indexed: 11/23/2022]
Abstract
Bisphenol A (BPA) is a ubiquitous industrial chemical used in the production of a wide variety of items. Previous studies suggest BPA exposure may result in neuro-disruptive effects; however, data are inconsistent across animal and human studies. As part of the Consortium Linking Academic and Regulatory Insights on BPA Toxicity (CLARITY-BPA), we sought to determine whether female and male rats developmentally exposed to BPA demonstrated later spatial navigational learning and memory deficits. Pregnant NCTR Sprague-Dawley rats were orally dosed from gestational day 6 to parturition, and offspring were directly orally dosed until weaning (postnatal day 21). Treatment groups included a vehicle control, three BPA doses (2.5μg/kg body weight (bw)/day-[2.5], 25μg/kg bw/day-[25], and 2500μg/kg bw/day-[2500]) and a 0.5μg/kg/day ethinyl estradiol (EE)-reference estrogen dose. At adulthood, 1/sex/litter was tested for seven days in the Barnes maze. The 2500 BPA group sniffed more incorrect holes on day 7 than those in the control, 2.5 BPA, and EE groups. The 2500 BPA females were less likely than control females to locate the escape box in the allotted time (p value=0.04). Although 2.5 BPA females exhibited a prolonged latency, the effect did not reach significance (p value=0.06), whereas 2.5 BPA males showed improved latency compared to control males (p value=0.04), although the significance of this result is uncertain. No differences in serum testosterone concentration were detected in any male or female treatment groups. Current findings suggest developmental exposure of rats to BPA may disrupt aspects of spatial navigational learning and memory.
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Affiliation(s)
- Sarah A Johnson
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, United States; Biomedical Sciences, University of Missouri, Columbia, MO 65211, United States
| | - Angela B Javurek
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, United States; Biomedical Sciences, University of Missouri, Columbia, MO 65211, United States
| | - Michele S Painter
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, United States; Biomedical Sciences, University of Missouri, Columbia, MO 65211, United States
| | - Mark R Ellersieck
- Agriculture Experimental Station-Statistics, University of Missouri, Columbia, MO 65211, United States
| | - Thomas H Welsh
- Department of Animal Science, Texas A&M University, College Station, TX 77843, United States
| | - Luísa Camacho
- Division of Biochemical Toxicology, National Center for Toxicological Research/Food and Drug Administration, Jefferson, AR 72079, United States
| | - Sherry M Lewis
- Office of Scientific Coordination, National Center for Toxicological Research/Food and Drug Administration, Jefferson, AR 72079, United States
| | - Michelle M Vanlandingham
- Division of Biochemical Toxicology, National Center for Toxicological Research/Food and Drug Administration, Jefferson, AR 72079, United States
| | - Sherry A Ferguson
- Division of Neurotoxicology, National Center for Toxicological Research/Food and Drug Administration, Jefferson, AR 72079, United States
| | - Cheryl S Rosenfeld
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, United States; Biomedical Sciences, University of Missouri, Columbia, MO 65211, United States; Genetics Area Program, University of Missouri, Columbia, MO 65211, United States; Thompson Center for Autism and Neurobehavioral Disorders, University of Missouri, Columbia, MO 65211, United States.
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10
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Sex-dependent effects of developmental exposure to bisphenol A and ethinyl estradiol on metabolic parameters and voluntary physical activity. J Dev Orig Health Dis 2015; 6:539-52. [PMID: 26378919 DOI: 10.1017/s2040174415001488] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Endocrine disrupting chemicals (EDC) have received considerable attention as potential obesogens. Past studies examining obesogenic potential of one widespread EDC, bisphenol A (BPA), have generally focused on metabolic and adipose tissue effects. However, physical inactivity has been proposed to be a leading cause of obesity. A paucity of studies has considered whether EDC, including BPA, affects this behavior. To test whether early exposure to BPA and ethinyl estradiol (EE, estrogen present in birth control pills) results in metabolic and such behavioral disruptions, California mice developmentally exposed to BPA and EE were tested as adults for energy expenditure (indirect calorimetry), body composition (echoMRI) and physical activity (measured by beam breaks and voluntary wheel running). Serum glucose and metabolic hormones were measured. No differences in body weight or food consumption were detected. BPA-exposed females exhibited greater variation in weight than females in control and EE groups. During the dark and light cycles, BPA females exhibited a higher average respiratory quotient than control females, indicative of metabolizing carbohydrates rather than fats. Various assessments of voluntary physical activity in the home cage confirmed that during the dark cycle, BPA and EE-exposed females were significantly less active in this setting than control females. Similar effects were not observed in BPA or EE-exposed males. No significant differences were detected in serum glucose, insulin, adiponectin and leptin concentrations. Results suggest that females developmentally exposed to BPA exhibit decreased motivation to engage in voluntary physical activity and altered metabolism of carbohydrates v. fats, which could have important health implications.
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11
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Miyaguchi T, Suemizu H, Shimizu M, Shida S, Nishiyama S, Takano R, Murayama N, Yamazaki H. Human urine and plasma concentrations of bisphenol A extrapolated from pharmacokinetics established in in vivo experiments with chimeric mice with humanized liver and semi-physiological pharmacokinetic modeling. Regul Toxicol Pharmacol 2015; 72:71-6. [DOI: 10.1016/j.yrtph.2015.03.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 03/15/2015] [Accepted: 03/18/2015] [Indexed: 11/26/2022]
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Iqbal K, Tran DA, Li AX, Warden C, Bai AY, Singh P, Wu X, Pfeifer GP, Szabó PE. Deleterious effects of endocrine disruptors are corrected in the mammalian germline by epigenome reprogramming. Genome Biol 2015; 16:59. [PMID: 25853433 PMCID: PMC4376074 DOI: 10.1186/s13059-015-0619-z] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 02/23/2015] [Indexed: 11/13/2022] Open
Abstract
Background Exposure to environmental endocrine-disrupting chemicals during pregnancy reportedly causes transgenerationally inherited reproductive defects. We hypothesized that to affect the grandchild, endocrine-disrupting chemicals must alter the epigenome of the germ cells of the in utero-exposed G1 male fetus. Additionally, to affect the great-grandchild, the aberration must persist in the germ cells of the unexposed G2 grandchild. Results Here, we treat gestating female mice with vinclozolin, bisphenol A, or di-(2-ethylhexyl)phthalate during the time when global de novo DNA methylation and imprint establishment occurs in the germ cells of the G1 male fetus. We map genome-wide features in purified G1 and G2 prospermatogonia, in order to detect immediate and persistent epigenetic aberrations, respectively. We detect changes in transcription and methylation in the G1 germline immediately after endocrine-disrupting chemicals exposure, but changes do not persist into the G2 germline. Additional analysis of genomic imprints shows no persistent aberrations in DNA methylation at the differentially methylated regions of imprinted genes between the G1 and G2 prospermatogonia, or in the allele-specific transcription of imprinted genes between the G2 and G3 soma. Conclusions Our results suggest that endocrine-disrupting chemicals exert direct epigenetic effects in exposed fetal germ cells, which are corrected by reprogramming events in the next generation. Avoiding transgenerational inheritance of environmentally-caused epigenetic aberrations may have played an evolutionary role in the development of dual waves of global epigenome reprogramming in mammals. Electronic supplementary material The online version of this article (doi:10.1186/s13059-015-0619-z) contains supplementary material, which is available to authorized users.
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Mattison DR, Karyakina N, Goodman M, LaKind JS. Pharmaco- and toxicokinetics of selected exogenous and endogenous estrogens: A review of the data and identification of knowledge gaps. Crit Rev Toxicol 2014; 44:696-724. [DOI: 10.3109/10408444.2014.930813] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Changes in memory and synaptic plasticity induced in male rats after maternal exposure to bisphenol A. Toxicology 2014; 322:51-60. [DOI: 10.1016/j.tox.2014.05.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Revised: 04/30/2014] [Accepted: 05/01/2014] [Indexed: 11/17/2022]
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Takaku T, Nagahori H, Sogame Y. Metabolism and physiologically based pharmacokinetic modeling of flumioxazin in pregnant animals. Toxicol Appl Pharmacol 2014; 277:242-9. [DOI: 10.1016/j.taap.2014.03.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 03/19/2014] [Accepted: 03/23/2014] [Indexed: 01/13/2023]
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Prediction and evaluation of route dependent dosimetry of BPA in rats at different life stages using a physiologically based pharmacokinetic model. Toxicol Appl Pharmacol 2013; 270:45-59. [DOI: 10.1016/j.taap.2013.03.022] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 02/25/2013] [Accepted: 03/18/2013] [Indexed: 11/23/2022]
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Williams SA, Jasarevic E, Vandas GM, Warzak DA, Geary DC, Ellersieck MR, Roberts RM, Rosenfeld CS. Effects of developmental bisphenol A exposure on reproductive-related behaviors in California mice (Peromyscus californicus): a monogamous animal model. PLoS One 2013; 8:e55698. [PMID: 23405200 PMCID: PMC3565966 DOI: 10.1371/journal.pone.0055698] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 01/02/2013] [Indexed: 11/28/2022] Open
Abstract
Bisphenol A (BPA), a pervasive, endocrine disrupting compound (EDC), acts as a mixed agonist-antagonist with respect to estrogens and other steroid hormones. We hypothesized that sexually selected traits would be particularly sensitive to EDC. Consistent with this concept, developmental exposure of males from the polygynous deer mouse, Peromyscus maniculatus, to BPA resulted in compromised spatial navigational ability and exploratory behaviors, while there was little effect on females. Here, we have examined a related, monogamous species, the California mouse (Peromyscus californicus), where we predicted that males would be less sensitive to BPA in terms of navigational and exploratory behaviors, while displaying other traits related to interactions with females and territorial marking that might be vulnerable to disruption. As in the deer mouse experiments, females were fed either a phytoestrogen-free CTL diet through pregnancy and lactation or the same diet supplemented with BPA (50 mg/kg feed weight) or ethinyl estradiol (EE) (0.1 part per billion) to provide a "pure" estrogen control. After weaning, pups were maintained on CTL diet until they had reached sexual maturity, at which time behaviors were evaluated. In addition, territorial marking was assessed in BPA-exposed males housed alone and when a control male was visible in the testing arena. In contrast to deer mice, BPA and EE exposure had no effect on spatial navigational skills in either male or female California mice. While CTL females exhibited greater exploratory behavior than CTL males, BPA exposure abolished this sex difference. BPA-exposed males, however, engaged in less territorial marking when CTL males were present. These studies demonstrate that developmental BPA exposure can disrupt adult behaviors in a sex- and species-dependent manner and are consistent with the hypothesis that sexually selected traits are particularly vulnerable to endocrine disruption and should be a consideration in risk assessment studies.
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Affiliation(s)
- Scott A. Williams
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States of America
| | - Eldin Jasarevic
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States of America
- Interdisciplinary Neuroscience Program, Center for Translational Neuroscience, University of Missouri, Columbia, Missouri, United States of America
- Department of Psychological Sciences, University of Missouri, Columbia, Missouri, United States of America
- Thompson Center for Autism and Neurodevelopmental Disorders, University of Missouri, Columbia, Missouri, United States of America
| | - Gregory M. Vandas
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States of America
| | - Denise A. Warzak
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
- Department of Animal Sciences, University of Missouri, Columbia, Missouri, United States of America
| | - David C. Geary
- Interdisciplinary Neuroscience Program, Center for Translational Neuroscience, University of Missouri, Columbia, Missouri, United States of America
- Department of Psychological Sciences, University of Missouri, Columbia, Missouri, United States of America
| | - Mark R. Ellersieck
- College of Agriculture, Food, and Natural Resources- Statistician, University of Missouri, Columbia, Missouri, United States of America
| | - R. Michael Roberts
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
- Department of Animal Sciences, University of Missouri, Columbia, Missouri, United States of America
- Department of Biochemistry, University of Missouri, Columbia, Missouri, United States of America
- Genetics Area Program, University of Missouri, Columbia, Missouri, United States of America
| | - Cheryl S. Rosenfeld
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri, United States of America
- Genetics Area Program, University of Missouri, Columbia, Missouri, United States of America
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri, United States of America
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Utturkar A, Paul B, Akkiraju H, Bonor J, Dhurjati P, Nohe A. Development of Physiologically Based Pharmacokinetic Model (PBPK) of BMP2 in Mice. ACTA ACUST UNITED AC 2013; 2. [PMID: 25485286 DOI: 10.4172/2329-6577.1000123] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Bone Morphogenetic protein 2 holds great promise for potential applications in the clinic. It is a potent growth factor for the use in the cervical spine surgery (FDA approved 2002) and has been marketed as "Infuse" for treating open tibial shaft fractures (FDA approved 2004). However, its use is limited by several significant side effects that maybe due to its potency and effect on different stem cell populations in the spine. BMP2 is expressed throughout the human body in several tissues and at a very high concentration in the blood. BMP receptors, especially BMP receptor type Ia, is ubiquitously expressed in most tissues. Currently, it is difficult to determine how BMP2 is physiologically distributed in mice or humans and no quantitative models are available. A Physiologically-Based Pharmaco-Kinetic (PBPK) model has been developed to determine steady-state distribution of BMP2 in mice. The multi-compartmental PBPK model represents relevant organ/tissues with physiological accuracy. The organs/tissue compartments chosen were brain, lung, heart, liver, pancreas, kidney, uterus, bone and fat. A blood compartment maintained connectivity among the various organs. Four processes characterized the change in the concentration of the protein in every compartment: blood flow in, blood flow out, protein turnover and receptor binding in the organ. The unique aspects of the model are the determination of elimination using receptor kinetics and generation using protein turnover. The model also predicts steady state concentrations of BMP2 in tissues in mice and may be used for possible scale-up of dosage regimens in humans.
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Affiliation(s)
- Aditya Utturkar
- Department of Chemical and Biomolecular Engineering, University of Delaware, USA
| | - Bikram Paul
- Department of Chemical and Biomolecular Engineering, University of Delaware, USA
| | | | - Jeremy Bonor
- Department of Biological Sciences, University of Delaware, USA
| | - Prasad Dhurjati
- Department of Chemical and Biomolecular Engineering, University of Delaware, USA
| | - Anja Nohe
- Department of Biological Sciences, University of Delaware, USA
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Jašarević E, Williams SA, Vandas GM, Ellersieck MR, Liao C, Kannan K, Roberts RM, Geary DC, Rosenfeld CS. Sex and dose-dependent effects of developmental exposure to bisphenol A on anxiety and spatial learning in deer mice (Peromyscus maniculatus bairdii) offspring. Horm Behav 2013; 63:180-9. [PMID: 23051835 PMCID: PMC3540128 DOI: 10.1016/j.yhbeh.2012.09.009] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 09/27/2012] [Accepted: 09/28/2012] [Indexed: 02/02/2023]
Abstract
Bisphenol A (BPA) is a widely produced, endocrine disrupting compound that is pervasive in the environment. Data suggest that developmental exposure to BPA during sexual differentiation of the brain leads to later behavioral consequences in offspring. Outbred deer mice (Peromyscus maniculatus bairdii) are an excellent animal model for such studies as they exhibit well-defined sex- and steroid-dependent behaviors. Here, dams during gestation and lactation were fed with a phytoestrogen-free control diet, the same diet supplemented with either ethinyl estradiol (0.1 ppb), or one of the three doses of BPA (50 mg, 5 mg, 50 μg/kg feed weight). After weaning, the pups were maintained on control diet until they reached sexual maturity and then assessed for both spatial learning capabilities and anxiety-like and exploratory behaviors. Relative to controls, males exposed to the two upper but not the lowest dose of BPA demonstrated similar impairments in spatial learning, increased anxiety and reduced exploratory behaviors as ethinyl estradiol-exposed males, while females exposed to ethinyl estradiol, but not to BPA, consistently exhibited masculinized spatial abilities. We also determined whether dams maintained chronically on the upper dose of BPA contained environmentally relevant concentrations of BPA in their blood. While serum concentrations of unconjugated BPA in controls were below the minimum level of detection, those from dams on the BPA diet were comparable (5.48±2.07 ng/ml) to concentrations that have been observed in humans. Together, these studies demonstrate that developmental exposure to environmentally relevant concentrations of BPA can disrupt adult behaviors in a dose- and sex-dependent manner.
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Affiliation(s)
- Eldin Jašarević
- Interdisciplinary Neuroscience Program, Center for Translational Neuroscience, University of Missouri, Columbia MO 65211
- Department of Psychological Sciences, University of Missouri, Columbia MO 65211
- Thompson Center for Autism and Neurodevelopmental Disorders, University of Missouri, Columbia MO 65211
| | - Scott A. Williams
- Division of Biological Sciences, University of Missouri, Columbia MO 65211
- Bond Life Sciences Center, University of Missouri, Columbia MO 65211
| | - Gregory M. Vandas
- Division of Biological Sciences, University of Missouri, Columbia MO 65211
- Bond Life Sciences Center, University of Missouri, Columbia MO 65211
| | - Mark R. Ellersieck
- College of Agriculture Food and Nutritional Resources-Statitician, University of Missouri, Columbia MO 65211
| | - Chunyang Liao
- Wadsworth Center, New York State Department of Health, and Department of Environmental Health Sciences, School of Public Health, State University of New York at Albany, Albany, NY
| | - Kurunthachalam Kannan
- Wadsworth Center, New York State Department of Health, and Department of Environmental Health Sciences, School of Public Health, State University of New York at Albany, Albany, NY
| | - R. Michael Roberts
- Bond Life Sciences Center, University of Missouri, Columbia MO 65211
- Department of Animal Sciences, University of Missouri, Columbia MO 65211
- Department of Biochemistry, University of Missouri, Columbia MO 65211
| | - David C. Geary
- Interdisciplinary Neuroscience Program, Center for Translational Neuroscience, University of Missouri, Columbia MO 65211
- Department of Psychological Sciences, University of Missouri, Columbia MO 65211
| | - Cheryl S. Rosenfeld
- Bond Life Sciences Center, University of Missouri, Columbia MO 65211
- Department of Biomedical Sciences, University of Missouri, Columbia MO 65211
- Corresponding author: Biomedical Sciences and Bond Life Sciences Center, University of Missouri, 440F Bond Life Sciences Center, 1201 E. Rollins Rd., Columbia, MO 65211. , phone: (573) 882-5132, and fax: (573) 884-9395.
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Vandenberg LN, Chahoud I, Heindel JJ, Padmanabhan V, Paumgartten FJ, Schoenfelder G. Urinary, Circulating, and Tissue Biomonitoring Studies Indicate Widespread Exposure to Bisphenol A. CIENCIA & SAUDE COLETIVA 2012; 17:407-34. [DOI: 10.1590/s1413-81232012000200015] [Citation(s) in RCA: 146] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Accepted: 03/23/2010] [Indexed: 11/21/2022] Open
Abstract
Bisphenol A (BPA) is one of the highest-volume chemicals produced worldwide, and human exposure to BPA is thought to be ubiquitous. Thus, there are concerns that the amount of BPA to which humans are exposed may cause adverse health effects. We examined many possibilities for why biomonitoring and toxicokinetic studies could come to seemingly conflicting conclusions. More than 80 published human biomonitoring studies that measured BPA concentrations in human tissues, urine, blood, and other fluids, along with two toxicokinetic studies of human BPA metabolism were examined. Unconjugated BPA was routinely detected in blood (in the nanograms per milliliter range), and conjugated BPA was routinely detected in the vast majority of urine samples (also in the nanograms per milliliter range). In stark contrast, toxicokinetic studies proposed that humans are not internally exposed to BPA. Available data from biomonitoring studies clearly indicate that the general population is exposed to BPA and is at risk from internal exposure to unconjugated BPA. The two toxicokinetic studies that suggested human BPA exposure is negligible have significant deficiencies, are directly contradicted by hypothesis-driven studies, and are therefore not reliable for risk assessment purposes.
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Pharmacokinetic modeling: Prediction and evaluation of route dependent dosimetry of bisphenol A in monkeys with extrapolation to humans. Toxicol Appl Pharmacol 2011; 257:122-36. [DOI: 10.1016/j.taap.2011.08.026] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Revised: 08/23/2011] [Accepted: 08/28/2011] [Indexed: 11/18/2022]
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Distribution of bisphenol A into tissues of adult, neonatal, and fetal Sprague-Dawley rats. Toxicol Appl Pharmacol 2011; 255:261-70. [PMID: 21820460 DOI: 10.1016/j.taap.2011.07.009] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 07/13/2011] [Accepted: 07/14/2011] [Indexed: 11/21/2022]
Abstract
Bisphenol A (BPA) is an important industrial chemical used in the manufacture of polycarbonate plastic products and epoxy resin-based food can liners. The presence of BPA metabolites in urine of >90% of Americans aged 6-60 suggests ubiquitous and frequent exposure in the range of 0.02-0.2μg/kgbw/d (25th-95th percentiles). The current study used LC/MS/MS to measure placental transfer and concentrations of aglycone (receptor-active) and conjugated (inactive) BPA in tissues from Sprague-Dawley rats administered deuterated BPA (100μg/kg bw) by oral and IV routes. In adult female rat tissues, the tissue/serum concentration ratios for aglycone BPA ranged from 0.7 in liver to 5 in adipose tissue, reflecting differences in tissue perfusion, composition, and metabolic capacity. Following IV administration to dams, placental transfer was observed for aglycone BPA into fetuses at several gestational days (GD), with fetal/maternal serum ratios of 2.7 at GD 12, 1.2 at GD 16, and 0.4 at GD 20; the corresponding ratios for conjugated BPA were 0.43, 0.65, and 3.7. These ratios were within the ranges observed in adult tissues and were not indicative of preferential accumulation of aglycone BPA or hydrolysis of conjugates in fetal tissue in vivo. Concentrations of aglycone BPA in GD 20 fetal brain were higher than in liver or serum. Oral administration of the same dose did not produce measurable levels of aglycone BPA in fetal tissues. Amniotic fluid consistently contained levels of BPA at or below those in maternal serum. Concentrations of aglycone BPA in tissues of neonatal rats decreased with age in a manner consistent with the corresponding circulating levels. Phase II metabolism of BPA increased with fetal age such that near-term fetus was similar to early post-natal rats. These results show that concentrations of aglycone BPA in fetal tissues are similar to those in other maternal and neonatal tissues and that maternal Phase II metabolism, especially following oral administration, and fetal age are critical in reducing exposures to the fetus.
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Biomonitoring Equivalents for bisphenol A (BPA). Regul Toxicol Pharmacol 2010; 58:18-24. [DOI: 10.1016/j.yrtph.2010.06.005] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Revised: 06/03/2010] [Accepted: 06/05/2010] [Indexed: 11/21/2022]
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Scientific Opinion on Bisphenol A: evaluation of a study investigating its neurodevelopmental toxicity, review of recent scientific literature on its toxicity and advice on the Danish risk assessment of Bisphenol A. EFSA J 2010. [DOI: 10.2903/j.efsa.2010.1829] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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Vandenberg LN, Chahoud I, Heindel JJ, Padmanabhan V, Paumgartten FJ, Schoenfelder G. Urinary, circulating, and tissue biomonitoring studies indicate widespread exposure to bisphenol A. ENVIRONMENTAL HEALTH PERSPECTIVES 2010; 118:1055-70. [PMID: 20338858 PMCID: PMC2920080 DOI: 10.1289/ehp.0901716] [Citation(s) in RCA: 907] [Impact Index Per Article: 64.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Accepted: 03/23/2010] [Indexed: 05/18/2023]
Abstract
BACKGROUND Bisphenol A (BPA) is one of the highest-volume chemicals produced worldwide, and human exposure to BPA is thought to be ubiquitous. Thus, there are concerns that the amount of BPA to which humans are exposed may cause adverse health effects. Importantly, results from a large number of biomonitoring studies are at odds with the results from two toxicokinetic studies. OBJECTIVE We examined several possibilities for why biomonitoring and toxicokinetic studies could come to seemingly conflicting conclusions. DATA SOURCES We examined > 80 published human biomonitoring studies that measured BPA concentrations in human tissues, urine, blood, and other fluids, along with two toxicokinetic studies of human BPA metabolism. DATA EXTRACTION AND SYNTHESIS The > 80 biomonitoring studies examined included measurements in thousands of individuals from several different countries, and these studies overwhelmingly detected BPA in individual adults, adolescents, and children. Unconjugated BPA was routinely detected in blood (in the nanograms per milliliter range), and conjugated BPA was routinely detected in the vast majority of urine samples (also in the nanograms per milliliter range). In stark contrast, toxicokinetic studies proposed that humans are not internally exposed to BPA. Some regulatory agencies have relied solely on these toxicokinetic models in their risk assessments. CONCLUSIONS Available data from biomonitoring studies clearly indicate that the general population is exposed to BPA and is at risk from internal exposure to unconjugated BPA. The two toxicokinetic studies that suggested human BPA exposure is negligible have significant deficiencies, are directly contradicted by hypothesis-driven studies, and are therefore not reliable for risk assessment purposes.
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Affiliation(s)
- Laura N. Vandenberg
- Tufts Center for Regenerative and Developmental Biology and
- Department of Biology, Tufts University, Medford, Massachusetts, USA
- Address correspondence to L.N. Vandenberg, Tufts University, Department of Biology, 200 Boston Ave., Suite 4600, Medford, MA 02155 USA. Telephone: (617) 627-4094. Fax: (617) 627-5305. E-mail:
| | - Ibrahim Chahoud
- Institut für Klinische Pharmakologie und Toxikologie, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Jerrold J. Heindel
- Division of Extramural Research and Training, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
| | - Vasantha Padmanabhan
- Department of Pediatrics
- Department of Obstetrics and Gynecology and
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Francisco J.R. Paumgartten
- Laboratory of Environmental Toxicology, National School of Public Health, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Gilbert Schoenfelder
- Institute of Pharmacology and Toxicology, University of Wuerzburg, Wuerzburg, Germany
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Willhite CC, Ball GL, McLellan CJ. Derivation of a bisphenol A oral reference dose (RfD) and drinking-water equivalent concentration. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2008; 11:69-146. [PMID: 18188738 DOI: 10.1080/10937400701724303] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Human exposure to bisphenol A (BPA) is due to that found in the diet, and BPA and its metabolites were detected at parts per billion (or less) concentrations in human urine, milk, saliva, serum, plasma, ovarian follicular fluid, and amniotic fluid. Adverse health effects in mice and rats may be induced after parenteral injection or after massive oral doses. Controlled ingestion trials in healthy adult volunteers with 5 mg d16-BPA were unable to detect parent BPA in plasma despite exquisitely sensitive (limit of detection = 6 nM) methods, but by 96 h 100% of the administered dose was recovered in urine as the glucuronide. The extensive BPA glucuronidation following ingestion is not seen after parenteral injection; only the parent BPA binds plasma proteins and estrogen receptors (ER). The hypothesis that BPA dose-response may be described by a J- or U-shape curve was not supported by toxicogenomic data collected in fetal rat testes and epididymes (after repeated parenteral exposure at 2-400,000 microg/kg-d), where a clear monotonic dose-response both in the numbers of genes and magnitude of individual gene expression was evident. There is no clear indication from available data that the BPA doses normally consumed by humans pose an increased risk for immunologic or neurologic disease. There is no evidence that BPA poses a genotoxic or carcinogenic risk and clinical evaluations of 205 men and women with high-performance liquid chromatography (HPLC)-verified serum or urinary BPA conjugates showed (1) no objective signs, (2) no changes in reproductive hormones or clinical chemistry parameters, and (3) no alterations in the number of children or sons:daughters ratio. Results of benchmark dose (BMD10 and BMDL10) calculations and no-observed-adverse-effect level (NOAEL) inspections of all available and reproducible rodent studies with oral BPA found BMD and NOAEL values all greater than the 5 mg/kg-d NOAELs from mouse and rat multigeneration reproduction toxicity studies. While allometric and physiologically based pharmacokinetic (PBPK) models were constructed for interspecies scaling of BPA and its interaction with ER, multigeneration feeding studies with BPA at doses spanning 5 orders of magnitude failed to identify signs of developmental toxicity or adverse changes in reproductive tract tissues; the 5-mg/kg-d NOAELs identified for systemic toxicity in rats and mice were less than the oral NOAELs for reproductive toxicity. Thus, it is the generalized systemic toxicity of ingested BPA rather than reproductive, immunologic, neurobehavioral, or genotoxic hazard that represents the point of departure. Using U.S. Environmental Protection Agency (EPA) uncertainty factor guidance and application of a threefold database uncertainty factor (to account for the fact that the carcinogenic potential of transplacental BPA exposure has yet to be fully defined and comprehensive neurobehavioral and immunotoxicologic evaluations of BPA by relevant routes and at relevant doses have yet to be completed) to the administered dose NOAEL results in an oral RfD of 0.016 mg/kg-d. Assuming the 70-kg adult consumes 2 L of water each day and adopting the default 20% U.S. EPA drinking water relative source contribution yields a 100 microg/L BPA total allowable concentration (TAC).
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Affiliation(s)
- Calvin C Willhite
- Department of Toxic Substances Control, State of California, Berkeley, California, USA
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