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Ferguson SA, Law CD, Abshire JS. Developmental Treatment with Bisphenol A or Ethinyl Estradiol Causes Few Alterations on Early Preweaning Measures. Toxicol Sci 2011; 124:149-60. [DOI: 10.1093/toxsci/kfr201] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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102
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Effect of bisphenol A on the cauda epididymis of adult male albino rats and the possible protective role of quercetin. ACTA ACUST UNITED AC 2011. [DOI: 10.1097/01.ehx.0000397468.63291.0c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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103
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Arnich N, Canivenc-Lavier MC, Kolf-Clauw M, Coffigny H, Cravedi JP, Grob K, Macherey AC, Masset D, Maximilien R, Narbonne JF, Nesslany F, Stadler J, Tulliez J. Conclusions of the French Food Safety Agency on the toxicity of bisphenol A. Int J Hyg Environ Health 2011; 214:271-5. [DOI: 10.1016/j.ijheh.2010.12.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 12/03/2010] [Accepted: 12/07/2010] [Indexed: 11/29/2022]
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104
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Orton F, Rosivatz E, Scholze M, Kortenkamp A. Widely used pesticides with previously unknown endocrine activity revealed as in vitro antiandrogens. ENVIRONMENTAL HEALTH PERSPECTIVES 2011. [PMID: 21310686 DOI: 10.1289/ehp.1002897] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
BACKGROUND Evidence suggests that there is widespread decline in male reproductive health and that antiandrogenic pollutants may play a significant role. There is also a clear disparity between pesticide exposure and data on endocrine disruption, with most of the published literature focused on pesticides that are no longer registered for use in developed countries. OBJECTIVE We used estimated human exposure data to select pesticides to test for antiandrogenic activity, focusing on highest use pesticides. METHODS We used European databases to select 134 candidate pesticides based on highest exposure, followed by a filtering step according to known or predicted receptor-mediated antiandrogenic potency, based on a previously published quantitative structure-activity relationship (QSAR) model. In total, 37 pesticides were tested for in vitro androgen receptor (AR) antagonism. Of these, 14 were previously reported to be AR antagonists ("active"), 4 were predicted AR antagonists using the QSAR, 6 were predicted to not be AR antagonists ("inactive"), and 13 had unknown activity, which were "out of domain" and therefore could not be classified with the QSAR ("unknown"). RESULTS All 14 pesticides with previous evidence of AR antagonism were confirmed as antiandrogenic in our assay, and 9 previously untested pesticides were identified as antiandrogenic (dimethomorph, fenhexamid, quinoxyfen, cyprodinil, λ-cyhalothrin, pyrimethanil, fludioxonil, azinphos-methyl, pirimiphos-methyl). In addition, we classified 7 compounds as androgenic. CONCLUSIONS Due to estimated antiandrogenic potency, current use, estimated exposure, and lack of previous data, we strongly recommend that dimethomorph, fludioxonil, fenhexamid, imazalil, ortho-phenylphenol, and pirimiphos-methyl be tested for antiandrogenic effects in vivo. The lack of human biomonitoring data for environmentally relevant pesticides presents a barrier to current risk assessment of pesticides on humans.
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Affiliation(s)
- Frances Orton
- Centre for Toxicology, School of Pharmacy, University of London, London, United Kingdom.
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105
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Orton F, Rosivatz E, Scholze M, Kortenkamp A. Widely used pesticides with previously unknown endocrine activity revealed as in vitro antiandrogens. ENVIRONMENTAL HEALTH PERSPECTIVES 2011; 119:794-800. [PMID: 21310686 PMCID: PMC3114813 DOI: 10.1289/ehp.1002895] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Accepted: 02/10/2011] [Indexed: 05/02/2023]
Abstract
BACKGROUND Evidence suggests that there is widespread decline in male reproductive health and that antiandrogenic pollutants may play a significant role. There is also a clear disparity between pesticide exposure and data on endocrine disruption, with most of the published literature focused on pesticides that are no longer registered for use in developed countries. OBJECTIVE We used estimated human exposure data to select pesticides to test for antiandrogenic activity, focusing on highest use pesticides. METHODS We used European databases to select 134 candidate pesticides based on highest exposure, followed by a filtering step according to known or predicted receptor-mediated antiandrogenic potency, based on a previously published quantitative structure-activity relationship (QSAR) model. In total, 37 pesticides were tested for in vitro androgen receptor (AR) antagonism. Of these, 14 were previously reported to be AR antagonists ("active"), 4 were predicted AR antagonists using the QSAR, 6 were predicted to not be AR antagonists ("inactive"), and 13 had unknown activity, which were "out of domain" and therefore could not be classified with the QSAR ("unknown"). RESULTS All 14 pesticides with previous evidence of AR antagonism were confirmed as antiandrogenic in our assay, and 9 previously untested pesticides were identified as antiandrogenic (dimethomorph, fenhexamid, quinoxyfen, cyprodinil, λ-cyhalothrin, pyrimethanil, fludioxonil, azinphos-methyl, pirimiphos-methyl). In addition, we classified 7 compounds as androgenic. CONCLUSIONS Due to estimated antiandrogenic potency, current use, estimated exposure, and lack of previous data, we strongly recommend that dimethomorph, fludioxonil, fenhexamid, imazalil, ortho-phenylphenol, and pirimiphos-methyl be tested for antiandrogenic effects in vivo. The lack of human biomonitoring data for environmentally relevant pesticides presents a barrier to current risk assessment of pesticides on humans.
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Affiliation(s)
- Frances Orton
- Centre for Toxicology, School of Pharmacy, University of London, London, United Kingdom.
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106
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Gualtieri AF, Iwachow MA, Venara M, Rey RA, Schteingart HF. Bisphenol A effect on glutathione synthesis and recycling in testicular Sertoli cells. J Endocrinol Invest 2011; 34:e102-9. [PMID: 20924222 DOI: 10.1007/bf03347468] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND AND OBJECTIVE Controversial effects of bisphenol A (BPA) have been reported on testicular function. These differences might reflect dissimilar exposure conditions. Dose responses to toxicants may be non-linear, e.g. U-shaped, with effects at low and at high levels of exposure and lower or inexistent effects at intermediate levels. Sertoli cells produce high levels of glutathione (GSH) as a cell defense mechanism. In this study, we addressed the question whether the exposure to different doses of BPA could influence Sertoli cell GSH synthesis and recycling. MATERIALS AND METHODS Primary Sertoli cell cultures were exposed to various doses of BPA (0.5 nM-100 μM). Cell viability was measured as an outcome of toxic effect. GSH cell content was determined to evaluate cell response to toxicant exposure. Glutamate-cysteine ligase catalytic (GCLC) and modulatory (GCLM) subunit expression were assessed to estimate GSH synthesis, and GSH reductase (GR) expression to estimate GSH recycling. RESULTS BPA 100 μM, but not lower doses, decreased cell viability. BPA 10 and 50 μM, but not lower doses, induced an increment in Sertoli cell GSH levels, due to a rapid upregulation of GCLC and GR and a slower upregulation of GCLM. CONCLUSIONS High doses of BPA are deleterious for Sertoli cells. Intermediate doses do not affect Sertoli cell viability and increase cell content of GSH owing to increased GSH synthesis and recycling enzyme expression. Lower doses of BPA are not capable of eliciting a cell defense response. These observations may explain a non-linear dose response of Sertoli cells to BPA.
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Affiliation(s)
- A F Gualtieri
- Centro de Investigaciones Endocrinológicas (CEDIE-CONICET), Hospital de Niños R. Gutiérrez, Gallo 1330, C1425EFD Buenos Aires, Argentina
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107
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Hengstler JG, Foth H, Gebel T, Kramer PJ, Lilienblum W, Schweinfurth H, Völkel W, Wollin KM, Gundert-Remy U. Critical evaluation of key evidence on the human health hazards of exposure to bisphenol A. Crit Rev Toxicol 2011; 41:263-91. [PMID: 21438738 PMCID: PMC3135059 DOI: 10.3109/10408444.2011.558487] [Citation(s) in RCA: 225] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Revised: 01/19/2011] [Accepted: 01/25/2011] [Indexed: 01/08/2023]
Abstract
Despite the fact that more than 5000 safety-related studies have been published on bisphenol A (BPA), there seems to be no resolution of the apparently deadlocked controversy as to whether exposure of the general population to BPA causes adverse effects due to its estrogenicity. Therefore, the Advisory Committee of the German Society of Toxicology reviewed the background and cutting-edge topics of this BPA controversy. The current tolerable daily intake value (TDI) of 0.05 mg/kg body weight [bw]/day, derived by the European Food Safety Authority (EFSA), is mainly based on body weight changes in two- and three-generation studies in mice and rats. Recently, these studies and the derivation of the TDI have been criticized. After having carefully considered all arguments, the Committee had to conclude that the criticism was scientifically not justified; moreover, recently published additional data further support the reliability of the two- and three-generation studies demonstrating a lack of estrogen-dependent effects at and below doses on which the current TDI is based. A frequently discussed topic is whether doses below 5 mg/kg bw/day may cause adverse health effects in laboratory animals. Meanwhile, it has become clear that positive results from some explorative studies have not been confirmed in subsequent studies with higher numbers of animals or a priori defined hypotheses. Particularly relevant are some recent studies with negative outcomes that addressed effects of BPA on the brain, behavior, and the prostate in rodents for extrapolation to the human situation. The Committee came to the conclusion that rodent data can well be used as a basis for human risk evaluation. Currently published conjectures that rats are insensitive to estrogens compared to humans can be refuted. Data from toxicokinetics studies show that the half-life of BPA in adult human subjects is less than 2 hours and BPA is completely recovered in urine as BPA-conjugates. Tissue deconjugation of BPA-glucuronide and -sulfate may occur. Because of the extremely low quantities, it is only of minor relevance for BPA toxicity. Biomonitoring studies have been used to estimate human BPA exposure and show that the daily intake of BPA is far below the TDI for the general population. Further topics addressed in this article include reasons why some studies on BPA are not reproducible; the relevance of oral versus non-oral exposure routes; the degree to which newborns are at higher systemic BPA exposure; increased BPA exposure by infusions in intensive care units; mechanisms of action other than estrogen receptor activation; and the current regulatory status in Europe, as well as in the USA, Canada, Japan, New Zealand, and Australia. Overall, the Committee concluded that the current TDI for BPA is adequately justified and that the available evidence indicates that BPA exposure represents no noteworthy risk to the health of the human population, including newborns and babies.
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Affiliation(s)
- J G Hengstler
- Leibniz Research Centre for Working Environment and Human Factors (IfADo), University of Dortmund, Dortmund, Germany.
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108
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Golub MS, Wu KL, Kaufman FL, Li LH, Moran-Messen F, Zeise L, Alexeeff GV, Donald JM. Bisphenol A: developmental toxicity from early prenatal exposure. ACTA ACUST UNITED AC 2011; 89:441-66. [PMID: 21136531 DOI: 10.1002/bdrb.20275] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Bisphenol A (BPA) exposure has been documented in pregnant women, but consequences for development are not yet widely studied in human populations. This review presents research on the consequences for offspring of BPA exposure during pregnancy. Extensive work in laboratory rodents has evaluated survival and growth of the conceptus, interference with embryonic programs of development, morphological sex differentiation, sex differentiation of the brain and behavior, immune responsiveness, and mechanism of action. Sensitive measures include RAR, aryl hydrocarbon receptor, and Hox A10 gene expression, anogenital distance, sex differentiation of affective and exploratory behavior, and immune hyperresponsiveness. Many BPA effects are reported at low doses (10-50 µg/kg d range) by the oral route of administration. At high doses (>500,000 µg/kg d) fetal viability is compromised. Much of the work has centered around the implications of the estrogenic actions of this agent. Some work related to thyroid mechanism of action has also been explored. BPA research has actively integrated current knowledge of developmental biology, concepts of endocrine disruption, and toxicological research to provide a basis for human health risk assessment.
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Affiliation(s)
- Mari S Golub
- Office of Environmental Health Hazard Assessment, Reproductive and Cancer Hazard Assessment Branch, Sacramento, California, USA.
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109
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Le HH, Belcher SM. Rapid signaling actions of environmental estrogens in developing granule cell neurons are mediated by estrogen receptor ß. Endocrinology 2010; 151:5689-99. [PMID: 20926581 PMCID: PMC2999500 DOI: 10.1210/en.2010-0710] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Estrogenic endocrine disrupting chemicals (EDCs) constitute a diverse group of man-made chemicals and natural compounds derived from plants and microbial metabolism. Estrogen-like actions are mediated via the nuclear hormone receptor activity of estrogen receptor (ER)α and ERβ and rapid regulation of intracellular signaling cascades. Previous study defined cerebellar granule cell neurons as estrogen responsive and that granule cell precursor viability was developmentally sensitive to estrogens. In this study experiments using Western blot analysis and pharmacological approaches have characterized the receptor and signaling modes of action of selective and nonselective estrogen ligands in developing cerebellar granule cells. Estrogen treatments were found to briefly increase ERK1/2-phosphorylation and then cause prolonged depression of ERK1/2 activity. The sensitivity of granule cell precursors to estrogen-induced cell death was found to require the integrated activation of membrane and intracellular ER signaling pathways. The sensitivity of granule cells to selective and nonselective ER agonists and a variety of estrogenic and nonestrogenic EDCs was also examined. The ERβ selective agonist DPN, but not the ERα selective agonist 4,4',4'-(4-propyl-[1H]-pyrazole-1,3,5-triyl) trisphenol or other ERα-specific ligands, stimulated cell death. Only EDCs with selective or nonselective ERβ activities like daidzein, equol, diethylstilbestrol, and bisphenol A were observed to induce E2-like neurotoxicity supporting the conclusion that estrogen sensitivity in granule cells is mediated via ERβ. The presented results also demonstrate the utility of estrogen sensitive developing granule cells as an in vitro assay for elucidating rapid estrogen-signaling mechanisms and to detect EDCs that act at ERβ to rapidly regulate intracellular signaling.
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Affiliation(s)
- Hoa H Le
- Department of Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0575, USA
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110
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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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111
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Rider CV, Furr JR, Wilson VS, Gray LE. Cumulative effects of in utero administration of mixtures of reproductive toxicants that disrupt common target tissues via diverse mechanisms of toxicity. ACTA ACUST UNITED AC 2010; 33:443-62. [PMID: 20487044 DOI: 10.1111/j.1365-2605.2009.01049.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Although risk assessments are typically conducted on a chemical-by-chemical basis, the 1996 Food Quality Protection Act required the US Environmental Protection Agency to consider cumulative risk of chemicals that act via a common mechanism of toxicity. To this end, we are conducting studies with mixtures of chemicals to elucidate mechanisms of joint action at the systemic level with the goal of providing a framework for assessing the cumulative effects of reproductive toxicants. Previous mixture studies conducted with antiandrogenic chemicals are reviewed briefly and two new studies are described. In all binary mixture studies, rats were dosed during pregnancy with chemicals, singly or in pairs, at dosage levels equivalent to approximately one-half of the ED50 for hypospadias or epididymal agenesis. The binary mixtures included androgen receptor (AR) antagonists (vinclozolin plus procymidone), phthalate esters [di(n-butyl) phthalate (DBP) plus benzyl n-butyl phthalate (BBP) and diethyl hexyl phthalate (DEHP) plus DBP], a phthalate ester plus an AR antagonist (DBP plus procymidone), a mixed mechanism androgen signalling disruptor (linuron) plus BBP, and two chemicals which disrupt epididymal differentiation through entirely different toxicity pathways: DBP (AR pathway) plus 2,3,7,8 TCDD (AhR pathway). We also conducted multi-component mixture studies combining several 'antiandrogens'. In the first study, seven chemicals (four pesticides and three phthalates) that elicit antiandrogenic effects at two different sites in the androgen signalling pathway (i.e. AR antagonist or inhibition of androgen synthesis) were combined. In the second study, three additional phthalates were added to make a 10 chemical mixture. In both the binary mixture studies and the multi-component mixture studies, chemicals that targeted male reproductive tract development displayed cumulative effects that exceeded predictions based on a response-addition model and most often were in accordance with predictions based on dose-addition models. In summary, our results indicate that compounds that act by disparate mechanisms of toxicity to disrupt the dynamic interactions among the interconnected signalling pathways in differentiating tissues produce cumulative dose-additive effects, regardless of the mechanism or mode of action of the individual mixture component.
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Affiliation(s)
- C V Rider
- MD-72, Reproductive Toxicology Branch, T A Division, NHEERL, ORD, US Environmental Protection Agency, RTP, NC 27711, USA
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112
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Lawson C, Gieske M, Murdoch B, Ye P, Li Y, Hassold T, Hunt PA. Gene expression in the fetal mouse ovary is altered by exposure to low doses of bisphenol A. Biol Reprod 2010; 84:79-86. [PMID: 20739668 DOI: 10.1095/biolreprod.110.084814] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Evidence from experimental studies suggests that fetal exposure to the endocrine-disrupting chemical bisphenol A (BPA) has adverse reproductive effects in both males and females. Studies from our laboratory suggest that exposure to the developing female fetus produces a unique, multigenerational effect. Specifically, maternal exposure affects the earliest stages of oogenesis in the developing fetal ovary, and the resulting subtle meiotic defects increase the likelihood that embryos produced by the exposed female in adulthood (i.e., the grandchildren) will be chromosomally abnormal. To understand the impact of BPA on the developing ovary, we conducted expression studies to characterize gene expression changes in the fetal ovary that result from BPA exposure. We first tested the validity of the approach, asking whether we could reliably detect temporal changes in expression levels of meiotic genes in controls. As anticipated, we were able to identify appropriate increases in expression in meiotic, but in few other, genes. Intriguingly, this analysis provided data on a small set of genes for which timing and expression changes suggest that they may have important and heretofore unrecognized meiotic roles. After verifying the utility of our approach, we focused our analysis on BPA-exposed animals. We found modest, but significant, changes in gene expression in the fetal ovaries from exposed fetuses. The first changes were evident within 24 h of exposure, and the most extensive changes correlated with the onset of meiosis. Furthermore, gene ontology analysis suggested that BPA acts to down-regulate mitotic cell-cycle genes, raising the possibility that fetal BPA exposure may act to limit expansion of the primordial germ cell population.
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Affiliation(s)
- Crystal Lawson
- School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, Washington 99164-7520, USA
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113
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Gray LE, Ryan B, Hotchkiss AK, Crofton KM. Rebuttal of "Flawed Experimental Design Reveals the Need for Guidelines Requiring Appropriate Positive Controls in Endocrine Disruption Research" by (Vom Saal 2010). Toxicol Sci 2010; 115:614-620. [PMID: 29910598 PMCID: PMC6002156 DOI: 10.1093/toxsci/kfq073] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
| | - Bryce Ryan
- University of Redlands, Biology Department, Redlands, CA
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114
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Affiliation(s)
- Richard M Sharpe
- Medical Research Council Human Reproductive Sciences Unit, Centre for Reproductive Biology, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom.
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115
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Lee KH, Park JH, Bunick D, Lubahn DB, Bahr JM. Morphological comparison of the testis and efferent ductules between wild-type and estrogen receptor alpha knockout mice during postnatal development. J Anat 2010; 214:916-25. [PMID: 19538635 DOI: 10.1111/j.1469-7580.2009.01080.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Estrogen and the estrogen receptor (ER)alpha play an important role in the male reproductive tract and in fertility. Previous studies demonstrated that disruption of ERalpha function resulted in abnormal morphology of the testis and efferent ductules (EDs) of adult mice. However, the effect of a lack of a functional ERalpha during early postnatal development has not been determined. The present study is an evaluation of morphological changes effected by a lack of ERalpha in the male reproductive tract during the postnatal period. Age-equivalent wild-type and ERalpha knockout (alphaERKO) mice at 10, 18, 35 and 60 days of age after birth were used for morphological comparison of the testes and ED. Light microscopic examination of the testes of the alphaERKO mouse revealed a dramatic dilation of the rete testis as early as 10 days of age, premature lumen formation, reduced epithelial height and greatly dilated lumen of seminiferous tubules as early as 18 days of age. The proximal ED of the alphaERKO mouse showed lumen dilation, reduction of epithelial height and a decrease of nuclear height as early as 10 days of age. Similar, but somewhat less severe, morphological abnormalities were observed in the distal ED of the alphaERKO mouse. These results indicate that a lack of functional ERalpha leads to morphological changes of the testis and ED of the early postnatal developing mouse. Based on these observations, we conclude that ERalpha plays an important role in normal development of the testis and ED, not only during adulthood but also during the entire postnatal period and presumably during fetal development.
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Affiliation(s)
- Ki-Ho Lee
- Department of Biochemistry and Molecular Biology, Medical Sciences Research Institute, Eulji University, Daejeon, Republic of Korea.
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116
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Stump DG, Beck MJ, Radovsky A, Garman RH, Freshwater LL, Sheets LP, Marty MS, Waechter JM, Dimond SS, Van Miller JP, Shiotsuka RN, Beyer D, Chappelle AH, Hentges SG. Developmental neurotoxicity study of dietary bisphenol A in Sprague-Dawley rats. Toxicol Sci 2010; 115:167-82. [PMID: 20164145 PMCID: PMC2855351 DOI: 10.1093/toxsci/kfq025] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Accepted: 01/22/2010] [Indexed: 11/13/2022] Open
Abstract
This study was conducted to determine the potential of bisphenol A (BPA) to induce functional and/or morphological effects to the nervous system of F(1) offspring from dietary exposure during gestation and lactation according to the Organization for Economic Cooperation and Development and U.S. Environmental Protection Agency guidelines for the study of developmental neurotoxicity. BPA was offered to female Sprague-Dawley Crl:CD (SD) rats (24 per dose group) and their litters at dietary concentrations of 0 (control), 0.15, 1.5, 75, 750, and 2250 ppm daily from gestation day 0 through lactation day 21. F(1) offspring were evaluated using the following tests: detailed clinical observations (postnatal days [PNDs] 4, 11, 21, 35, 45, and 60), auditory startle (PNDs 20 and 60), motor activity (PNDs 13, 17, 21, and 61), learning and memory using the Biel water maze (PNDs 22 and 62), and brain and nervous system neuropathology and brain morphometry (PNDs 21 and 72). For F(1) offspring, there were no treatment-related neurobehavioral effects, nor was there evidence of neuropathology or effects on brain morphometry. Based on maternal and offspring body weight reductions, the no-observed-adverse-effect level (NOAEL) for systemic toxicity was 75 ppm (5.85 and 13.1 mg/kg/day during gestation and lactation, respectively), with no treatment-related effects at lower doses or nonmonotonic dose responses observed for any parameter. There was no evidence that BPA is a developmental neurotoxicant in rats, and the NOAEL for developmental neurotoxicity was 2250 ppm, the highest dose tested (164 and 410 mg/kg/day during gestation and lactation, respectively).
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Affiliation(s)
- Donald G Stump
- Developmental and Reproductive Toxicology, WIL Research Laboratories, LLC, Ashland, Ohio 44805-8946, USA.
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117
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Sharpe RM. Is it time to end concerns over the estrogenic effects of bisphenol A? Toxicol Sci 2010; 114:1-4. [PMID: 20147444 DOI: 10.1093/toxsci/kfp299] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Richard M Sharpe
- Medical Research Council Human Reproductive Sciences Unit, Centre for Reproductive Biology, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh EH16 4TJ, UK.
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118
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Caldwell DJ, Mastrocco F, Nowak E, Johnston J, Yekel H, Pfeiffer D, Hoyt M, DuPlessie BM, Anderson PD. An assessment of potential exposure and risk from estrogens in drinking water. ENVIRONMENTAL HEALTH PERSPECTIVES 2010; 118:338-344. [PMID: 20194073 PMCID: PMC2854760 DOI: 10.1289/ehp.0900654] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Accepted: 10/13/2009] [Indexed: 05/26/2023]
Abstract
BACKGROUND Detection of estrogens in the environment has raised concerns in recent years because of their potential to affect both wildlife and humans. OBJECTIVES We compared exposures to prescribed and naturally occurring estrogens in drinking water to exposures to naturally occurring background levels of estrogens in the diet of children and adults and to four independently derived acceptable daily intakes (ADIs) to determine whether drinking water intakes are larger or smaller than dietary intake or ADIs. METHODS We used the Pharmaceutical Assessment and Transport Evaluation (PhATE) model to predict concentrations of estrogens potentially present in drinking water. Predicted drinking water concentrations were combined with default water intake rates to estimate drinking water exposures. Predicted drinking water intakes were compared to dietary intakes and also to ADIs. We present comparisons for individual estrogens as well as combined estrogens. RESULTS In the analysis we estimated that a child's exposures to individual prescribed estrogens in drinking water are 730-480,000 times lower (depending upon estrogen type) than exposure to background levels of naturally occurring estrogens in milk. A child's exposure to total estrogens in drinking water (prescribed and naturally occurring) is about 150 times lower than exposure from milk. Adult margins of exposure (MOEs) based on total dietary exposure are about 2 times smaller than those for children. Margins of safety (MOSs) for an adult's exposure to total prescribed estrogens in drinking water vary from about 135 to > 17,000, depending on ADI. MOSs for exposure to total estrogens in drinking water are about 2 times lower than MOSs for prescribed estrogens. Depending on the ADI that is used, MOSs for young children range from 28 to 5,120 for total estrogens (including both prescribed and naturally occurring sources) in drinking water. CONCLUSIONS The consistently large MOEs and MOSs strongly suggest that prescribed and total estrogens that may potentially be present in drinking water in the United States are not causing adverse effects in U.S. residents, including sensitive subpopulations.
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Affiliation(s)
- Daniel J. Caldwell
- Johnson & Johnson Worldwide Environment, Health, and Safety, New Brunswick, New Jersey, USA
| | | | - Edward Nowak
- Johnson & Johnson Pharmaceutical Research and Development, Raritan, New Jersey, USA
| | | | | | | | - Marilyn Hoyt
- AMEC Earth & Environmental, Westford, Massachusetts, USA
| | | | - Paul D. Anderson
- ARCADIS, Chelmsford, Massachusetts, USA
- Department of Geography and Environment, Boston University, Boston, Massachusetts, USA
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vom Saal FS, Akingbemi BT, Belcher SM, Crain DA, Crews D, Guidice LC, Hunt PA, Leranth C, Myers JP, Nadal A, Olea N, Padmanabhan V, Rosenfeld CS, Schneyer A, Schoenfelder G, Sonnenschein C, Soto AM, Stahlhut RW, Swan SH, Vandenberg LN, Wang HS, Watson CS, Welshons WV, Zoeller RT. Flawed Experimental Design Reveals the Need for Guidelines Requiring Appropriate Positive Controls in Endocrine Disruption Research. Toxicol Sci 2010; 115:612-3. [DOI: 10.1093/toxsci/kfq048] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Sharpe RM. Bisphenol A exposure and sexual dysfunction in men: editorial commentary on the article 'Occupational exposure to bisphenol-A (BPA) and the risk of self-reported male sexual dysfunction' Li et al., 2009. Hum Reprod 2009; 25:292-4. [PMID: 19906655 DOI: 10.1093/humrep/dep385] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Tyl RW. Basic exploratory research versus guideline-compliant studies used for hazard evaluation and risk assessment: bisphenol A as a case study. ENVIRONMENTAL HEALTH PERSPECTIVES 2009; 117:1644-51. [PMID: 20049112 PMCID: PMC2801172 DOI: 10.1289/ehp.0900893] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2009] [Accepted: 06/29/2009] [Indexed: 05/17/2023]
Abstract
BACKGROUND Myers et al. [Environ Health Perspect 117:309-315 (2009)] argued that Good Laboratory Practices (GLPs) cannot be used as a criterion for selecting data for risk assessment, using bisphenol A (BPA) as a case study. They did not discuss the role(s) of guideline-compliant studies versus basic/exploratory research studies, and they criticized both GLPs and guideline-compliant studies and their roles in formal hazard evaluation and risk assessment. They also specifically criticized our published guideline-compliant dietary studies on BPA in rats and mice and 17beta-estradiol (E(2)) in mice. OBJECTIVES As the study director/first author of the criticized E(2) and BPA studies, I discuss the uses of basic research versus guideline-compliant studies, how testing guidelines are developed and revised, how new end points are validated, and the role of GLPs. I also provide an overview of the BPA guideline-compliant and exploratory research animal studies and describe BPA pharmacokinetics in rats and humans. I present responses to specific criticisms by Myers et al. DISCUSSION AND CONCLUSIONS Weight-of-evidence evaluations have consistently concluded that low-level BPA oral exposures do not adversely affect human developmental or reproductive health, and I encourage increased validation efforts for "new" end points for inclusion in guideline studies, as well as performance of robust long-term studies to follow early effects (observed in small exploratory studies) to any adverse consequences.
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Affiliation(s)
- Rochelle W Tyl
- RTI International, Research Triangle Park, North Carolina 27709-2194, USA.
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Ryan BC, Hotchkiss AK, Crofton KM, Gray LE. In Utero and Lactational Exposure to Bisphenol A, In Contrast to Ethinyl Estradiol, Does Not Alter Sexually Dimorphic Behavior, Puberty, Fertility, and Anatomy of Female LE Rats. Toxicol Sci 2009; 114:133-48. [DOI: 10.1093/toxsci/kfp266] [Citation(s) in RCA: 142] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Mathews E, Braden TD, Williams CS, Williams JW, Bolden-Tiller O, Goyal HO. Mal-development of the penis and loss of fertility in male rats treated neonatally with female contraceptive 17alpha-ethinyl estradiol: a dose-response study and a comparative study with a known estrogenic teratogen diethylstilbestrol. Toxicol Sci 2009; 112:331-43. [PMID: 19729556 DOI: 10.1093/toxsci/kfp207] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The objectives of this study were to find a minimal dose of 17alpha-ethinyl estradiol (EE) that is detrimental to the developing penis and fertility and to compare estrogenic effects between EE and diethylstilbestrol (DES). Neonatal rats received EE at 10 ng (1 microg/kg), 100 ng, 1 microg, or 10 microg per pup on alternate days from postnatal days 1 to 11 (dose-response study) or received EE or DES at 100 ng per pup daily from postnatal days 1 to 6 (comparative study). Effects of EE were dose dependent, with > or = 100-ng dose inducing significant (p < 0.05) reductions in penile length, weight, and diameter. Additionally, the penis was malformed, characterized by underdeveloped os penis and accumulation of fat cells. Fertility was 0% in the > or = 1-microg groups, in contrast to 60% in the 100-ng group and 100% in the 10-ng and control groups. Animals treated with > or = 10 ng had significant reductions in the weight of bulbospongious muscle, testis, seminal vesicle, epididymal fat pad, and in epididymal sperm numbers. A comparison of EE and DES effects showed similar reductions in penile weight and length and the weight of bulbospongiosus muscle, testis, seminal vesicle, epididymis, and epididymal fat pad in both adolescent and adult rats. While 5/6 control males sired, only 1/6 in the EE group and 0/6 in the DES group sired. Hence, neonatal exposure to EE at 10 ng (environmentally relevant dose) adversely affects male reproductive organs. A dose ten times higher than this leads to permanently mal-developed penis and infertility. Furthermore, EE and DES exposures show similar level of toxicity to male reproductive organs.
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Affiliation(s)
- Ensa Mathews
- Department of Biomedical Sciences, College of Veterinary Medicine, Tuskegee University, Tuskegee, Alabama 36088, USA
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Ceccarelli I, Fiorenzani P, Della Seta D, Massafra C, Cinci G, Bocci A, Aloisi AM. Perinatal exposure to xenoestrogens affects pain in adult female rats. Neurotoxicol Teratol 2009; 31:203-9. [DOI: 10.1016/j.ntt.2009.02.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2008] [Revised: 01/27/2009] [Accepted: 02/16/2009] [Indexed: 11/25/2022]
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Goodman JE, Witorsch RJ, McConnell EE, Sipes IG, Slayton TM, Yu CJ, Franz AM, Rhomberg LR. Weight-of-Evidence Evaluation of Reproductive and Developmental Effects of Low Doses of Bisphenol A. Crit Rev Toxicol 2009. [DOI: 10.1080/10408440802157839] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Hotchkiss AK, Rider CV, Blystone CR, Wilson VS, Hartig PC, Ankley GT, Foster PM, Gray CL, Gray LE. Fifteen years after "Wingspread"--environmental endocrine disrupters and human and wildlife health: where we are today and where we need to go. Toxicol Sci 2008; 105:235-59. [PMID: 18281716 DOI: 10.1093/toxsci/kfn030] [Citation(s) in RCA: 328] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
In 1991, a group of expert scientists at a Wingspread work session on endocrine-disrupting chemicals (EDCs) concluded that "Many compounds introduced into the environment by human activity are capable of disrupting the endocrine system of animals, including fish, wildlife, and humans. Endocrine disruption can be profound because of the crucial role hormones play in controlling development." Since that time, there have been numerous documented examples of adverse effects of EDCs in invertebrates, fish, wildlife, domestic animals, and humans. Hormonal systems can be disrupted by numerous different anthropogenic chemicals including antiandrogens, androgens, estrogens, AhR agonists, inhibitors of steroid hormone synthesis, antithyroid substances, and retinoid agonists. In addition, pathways and targets for endocrine disruption extend beyond the traditional estrogen/androgen/thyroid receptor-mediated reproductive and developmental systems. For example, scientists have expressed concern about the potential role of EDCs in increasing trends in early puberty in girls, obesity and type II diabetes in the United States and other populations. New concerns include complex endocrine alterations induced by mixtures of chemicals, an issue broadened due to the growing awareness that EDCs present in the environment include a variety of potent human and veterinary pharmaceutical products, personal care products, nutraceuticals and phytosterols. In this review we (1) address what have we learned about the effects of EDCs on fish, wildlife, and human health, (2) discuss representative animal studies on (anti)androgens, estrogens and 2,3,7,8-tetrachlorodibenzo-p-dioxin-like chemicals, and (3) evaluate regulatory proposals being considered for screening and testing these chemicals.
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Affiliation(s)
- Andrew K Hotchkiss
- USEPA/NCSU Cooperative Training agreement (CT826512010), Raleigh, North Carolina 27695, USA
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