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Reho JJ, Muskus PC, Bennett DM, Grobe CC, Burnett CML, Nakagawa P, Segar JL, Sigmund CD, Grobe JL. Modulatory effects of estrous cycle on ingestive behaviors and energy balance in young adult C57BL/6J mice maintained on a phytoestrogen-free diet. Am J Physiol Regul Integr Comp Physiol 2024; 326:R242-R253. [PMID: 38284128 PMCID: PMC11213288 DOI: 10.1152/ajpregu.00273.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 01/17/2024] [Accepted: 01/22/2024] [Indexed: 01/30/2024]
Abstract
The estrous cycle is known to modify food, fluid, and electrolyte intake behaviors and energy homeostasis in various species, in part through fluctuations in estrogen levels. Simultaneously, commonly commercially available rodent dietary formulations greatly vary in soy protein content, and thereby the delivery of biologically active phytoestrogens. To explore the interactions among the estrous cycle, sodium, fluid, and caloric seeking behaviors, and energy homeostasis, young adult C57BL/6J female mice were maintained on a soy protein-free 2920x diet and provided water, or a choice between water and 0.15 mol/L NaCl drink solution. Comprehensive metabolic phenotyping was performed using a multiplexed Promethion (Sable Systems International) system, and estrous stages were determined via daily vaginal cytology. When provided food and water, estrous cycling had no major modulatory effects on intake behaviors or energy balance. When provided a saline solution drink choice, significant modulatory effects of the transition from diestrus to proestrus were observed upon fluid intake patterning, locomotion, and total energy expenditure. Access to saline increased total daily sodium consumption and aspects of energy expenditure, but these effects were not modified by the estrous stage. Collectively, these results indicate that when supplied a phytoestrogen-free diet, the estrous cycle has minor modulatory effects on ingestive behaviors and energy balance in C57BL/6J mice that are sensitive to sodium supply.NEW & NOTEWORTHY When provided a phytoestrogen-free diet, the estrous cycle had very little effect on food and water intake, physical activity, or energy expenditure in C57BL/6J mice. In contrast, when provided an NaCl drink in addition to food and water, the estrous cycle was associated with changes in intake behaviors and energy expenditure. These findings highlight the complex interactions among estrous cycling, dietary formulation, and nutrient presentation upon ingestive behaviors and energy homeostasis in mice.
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Affiliation(s)
- John J Reho
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Comprehensive Rodent Metabolic Phenotyping Core, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Patricia C Muskus
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Darby M Bennett
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Connie C Grobe
- Department of Pediatrics, Division of Neonatology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Colin M L Burnett
- Department of Medicine/Division of Cardiovascular Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Pablo Nakagawa
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Jeffrey L Segar
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Department of Pediatrics, Division of Neonatology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Curt D Sigmund
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Justin L Grobe
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Comprehensive Rodent Metabolic Phenotyping Core, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Neuroscience Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
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2
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Nuñez P, Arguelles J, Perillan C. Sex-specific influence of maternal exposure to bisphenol A on sodium and fluid balance in response to dipsogenic challenges in rats. Appetite 2022; 176:106091. [DOI: 10.1016/j.appet.2022.106091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 05/06/2022] [Accepted: 05/18/2022] [Indexed: 11/30/2022]
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3
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Boudalia S, Bousbia A, Boumaaza B, Oudir M, Canivenc Lavier MC. Relationship between endocrine disruptors and obesity with a focus on bisphenol A: a narrative review. BIOIMPACTS 2021; 11:289-300. [PMID: 34631491 PMCID: PMC8494257 DOI: 10.34172/bi.2021.33] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 04/25/2020] [Accepted: 05/10/2020] [Indexed: 11/09/2022]
Abstract
Introduction: Scientific data suggest that early exposure to endocrine-disrupting chemicals (EDCs) affect -repro, -neuro, -metabolic systems, to which are added other notions such as mixtures, window and duration of exposure, trans-generational effects, and epigenetic mechanisms. Methods: In the present narrative review, we studied the relationship between exposure to EDCs with the appearance and development of obesity. Results: Exposure to EDCs like Bisphenol A during the early stages of development has been shown to lead to weight gain and obesity. EDCs can interfere with endocrine signaling, affect adipocytes differentiation and endocrine function and disrupt metabolic processes, especially if exposure occurs at very low doses, in the mixture, during early development stages for several generations. Conclusion: Exposure to EDCs is positively associated with obesity development. Moreover, the use of integrative approaches which mimicking environmental conditions are necessary and recommended to evaluate EDCs' effects in future studies.
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Affiliation(s)
- Sofiane Boudalia
- Faculté des Sciences de la Nature et de la Vie et Sciences de la Terre et de l'Univers, Université 8 Mai 1945 Guelma BP 4010 Guelma 24000, Algérie.,Laboratoire de Biologie, Eau et Environnement, Université 8 Mai 1945 Guelma BP 4010 Guelma 24000, Algérie
| | - Aissam Bousbia
- Faculté des Sciences de la Nature et de la Vie et Sciences de la Terre et de l'Univers, Université 8 Mai 1945 Guelma BP 4010 Guelma 24000, Algérie.,Laboratoire de Biologie, Eau et Environnement, Université 8 Mai 1945 Guelma BP 4010 Guelma 24000, Algérie
| | - Boualem Boumaaza
- Laboratoire de Biologie, Eau et Environnement, Université 8 Mai 1945 Guelma BP 4010 Guelma 24000, Algérie.,Département des Sciences Agronomiques, Faculté des Sciences de la Nature et de la Vie, Université Ibn Khaldoun, Tiaret 14000, Algérie
| | - Malha Oudir
- Laboratoire de Génie Chimique, Département de Génie des Procédés, Faculté de Technologie, Université Saâd Dahlab, USDB. BP 270, Route de Soumâa, 09000 Blida, Algérie
| | - Marie Chantal Canivenc Lavier
- Centre des Sciences du Goût et de l'Alimentation, INRA, CNRS, Université de Bourgogne - Franche-Comté, Dijon, 21000, France
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4
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Vom Saal FS. Flaws in design, execution and interpretation limit CLARITY-BPA's value for risk assessments of bisphenol A. Basic Clin Pharmacol Toxicol 2019; 125 Suppl 3:32-43. [PMID: 30589220 DOI: 10.1111/bcpt.13195] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 12/14/2018] [Indexed: 11/27/2022]
Abstract
The Consortium Linking Academic and Regulatory Insights on BPA Toxicity (CLARITY-BPA) involved the Food and Drug Administration, the National Toxicology Program and 14 academic investigators funded by the National Institute of Environmental Health Sciences. Two key questions to be answered by CLARITY-BPA were as follows: (1) Would the academic investigator studies show effects at low doses of bisphenol A (BPA) while the core guideline study conducted by the FDA only showed toxic effects at high doses? (2) Would the academic investigators be able to replicate their numerous prior studies with animals raised and treated in the FDA's toxicology centre? Several flaws in the design and execution of CLARITY-BPA biased the experiment towards not finding significant results (Type 2 error): (1) use of the oestrogen-insensitive NCTR CD-SD rat, (2) use of a stressful daily gavage BPA administration procedure throughout life, (3) lack of inclusion of non-gavaged negative controls and (4) lack of a comprehensive examination of animals for BPA contamination. In spite of these flaws, in some of the experiments conducted by CLARITY-BPA academic investigators, and also in the FDA's core study, there were significant low-dose effects, but these were ignored by the FDA. Thus, immediately after releasing the results from their core portion of CLARITY-BPA, the FDA issued a statement concluding BPA was "safe," and they ignored non-monotonic dose-response relationships. The FDA should not base its BPA risk assessment only on outdated guideline studies, but instead on the vast (~8000) number of publications documenting the similar health hazards BPA poses to animals and humans.
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Affiliation(s)
- Frederick S Vom Saal
- Division of Biological Sciences, University of Missouri-Columbia, Columbia, Missouri
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5
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Catanese MC, Vandenberg LN. Low doses of 17α-ethinyl estradiol alter the maternal brain and induce stereotypies in CD-1 mice exposed during pregnancy and lactation. Reprod Toxicol 2017; 73:20-29. [PMID: 28736173 DOI: 10.1016/j.reprotox.2017.07.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 07/12/2017] [Accepted: 07/14/2017] [Indexed: 01/08/2023]
Abstract
Maternal care is critical for the survival, development and long-term success of offspring. Despite our current understanding of the role of endogenous estrogen in both maternal behavior and the maternal brain, the potential effects of exogenous estrogens on these endpoints remain poorly understood. Here, pregnant CD-1 mice were exposed to low doses of 17α-ethinyl estradiol (EE2), commonly used as a positive control in studies of other xenoestrogens, from day 9 of pregnancy until weaning. Using traditional maternal behavior assays, we document no significant changes in maternal behavior throughout the lactational period. However, EE2 induced increases in repetitive tail retrieval, which may indicate a stereotypy or obsessive compulsive (OCD)-like behavior. We also observed a significant reduction in tyrosine hydroxylase (TH) immunoreactivity in the ventral tegmental area (VTA), a region important for maternal motivation. These results suggest that pregnant adult females are not immune to the effects of this compound.
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Affiliation(s)
- Mary C Catanese
- Program in Neuroscience and Behavior, University of Massachusetts, Amherst, USA
| | - Laura N Vandenberg
- Program in Neuroscience and Behavior, University of Massachusetts, Amherst, USA; Department of Environmental Health Sciences, School of Public Health and Health Sciences, University of Massachusetts, Amherst, USA.
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Boudalia S, Belloir C, Miller ML, Canivenc-Lavier MC. Early endocrine disruptors exposure acts on 3T3-L1 differentiation and endocrine activity. ACTA ACUST UNITED AC 2017; 7:83-89. [PMID: 28752072 PMCID: PMC5524989 DOI: 10.15171/bi.2017.11] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Revised: 02/06/2017] [Accepted: 03/13/2017] [Indexed: 11/09/2022]
Abstract
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Introduction: Data from last years suggested that early exposure to endocrine disruptors (EDs) can predispose newborns to endocrine dysfunction of adipocytes, obesity, and associated disorders. The implication of EDs at low doses on adipocyte development has been poorly investigated. For instance, vinclozolin (V) is a dicarboximide fungicide widely used in agriculture since the 90's, alone or in mixture with genistein (G), an isoflavonoid from Leguminosae. This study aims to identify the effect of vinclozolin alone or with genistein, on adipose tissue properties using cell culture.
Methods: In steroid-free conditions, 3T3-L1 pre-adipocytes were induced to differentiate in the presence of EDs, singularly or in mixtures, for 2 days. DNA and triglyceride (TG) levels were measured on days 0, 2 and 8 of differentiation. Leptin secretion was measured only on the eighth day.
Results: We show that low doses of G (25 µM) and V (0.1 µM) inhibit pre-adipocytes differentiation. This inhibition has been represented by a decreasing in DNA content (µg/well) and decreasing in TG accumulation (mg/mL) in 3T3-L1 cells. Nevertheless, V increased the anti-adipogenic properties of G.
Conclusion: This study confirms that EDs singularly or in mixtures, introduced during early stages of life, could affect the differentiation and the endocrine activity of adipocytes, and can act as potential factors for obesity.
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Affiliation(s)
- Sofiane Boudalia
- INRA, UMR1324, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,CNRS, UMR6265, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,Département d'Ecologie et Génie de l'Environnement, Université 8 Mai 1945, Guelma, Algérie.,Laboratoire de Biologie, Eau et Environnement, Université 8 Mai 1945, Guelma, Algérie
| | - Christine Belloir
- INRA, UMR1324, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,CNRS, UMR6265, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France
| | - Marie-Louise Miller
- INRA, UMR1324, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,CNRS, UMR6265, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France
| | - Marie-Chantal Canivenc-Lavier
- INRA, UMR1324, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,CNRS, UMR6265, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France.,Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, F-21000 Dijon, France
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Ceccarelli I, Fiorenzani P, Della Seta D, Aloisi AM. Perinatal 17α-ethinylestradiol exposure affects formalin-induced responses in middle-aged male (but not female) rats. Horm Behav 2015; 73:116-24. [PMID: 26159286 DOI: 10.1016/j.yhbeh.2015.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 06/16/2015] [Accepted: 07/01/2015] [Indexed: 11/27/2022]
Abstract
17α-Ethinylestradiol (EE), the main component of the contraceptive pill, is a synthetic estrogen found in rivers of the United States and Europe as an environmental contaminant. It is one of the most studied xenoestrogens due to its possible effect on the reproductive system. In the present study we evaluated the modulation of pain responses induced by formalin injection (licking, flexing, paw-jerk) in 8-month-old male and female offspring of female rats treated with two different doses of EE (4ng/kg/day or 400ng/kg/day) during pregnancy and lactation. Spontaneous behaviors and gonadal hormone levels were also determined. Both concentrations of EE induced an increase of pain behaviors in males only, i.e. higher flexing and licking of the formalin-injected paw than in OIL-exposed rats, during the second, inflammatory, phase of the formalin test. Grooming duration was increased by EE exposure in both males and females. Prenatal EE exposure (both concentrations) decreased estradiol plasma levels in the formalin-injected females but not in the males. These results underline the possibility that exposure to an environmental contaminant during the critical period of development can affect neural processes (such as those involved in pain modulation) during adulthood, indicating long-term changes in brain circuitry. However, such changes may be different in males and females.
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Affiliation(s)
- Ilaria Ceccarelli
- Department of Medicine, Surgery and Neuroscience, University of Siena, via Aldo Moro, 2, 53100 Siena, Italy
| | - Paolo Fiorenzani
- Department of Medicine, Surgery and Neuroscience, University of Siena, via Aldo Moro, 2, 53100 Siena, Italy
| | - Daniele Della Seta
- Department of Medicine, Surgery and Neuroscience, University of Siena, via Aldo Moro, 2, 53100 Siena, Italy
| | - Anna Maria Aloisi
- Department of Medicine, Surgery and Neuroscience, University of Siena, via Aldo Moro, 2, 53100 Siena, Italy.
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8
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Mecawi AS, Macchione AF, Nuñez P, Perillan C, Reis LC, Vivas L, Arguelles J. Developmental programing of thirst and sodium appetite. Neurosci Biobehav Rev 2015; 51:1-14. [DOI: 10.1016/j.neubiorev.2014.12.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 12/05/2014] [Accepted: 12/09/2014] [Indexed: 01/17/2023]
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Ferguson SA, Law CD, Kissling GE. Developmental treatment with ethinyl estradiol, but not bisphenol A, causes alterations in sexually dimorphic behaviors in male and female Sprague Dawley rats. Toxicol Sci 2014; 140:374-92. [PMID: 24798382 PMCID: PMC4133561 DOI: 10.1093/toxsci/kfu077] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 04/17/2014] [Indexed: 01/26/2023] Open
Abstract
The developing central nervous system may be particularly sensitive to bisphenol A (BPA)-induced alterations. Here, pregnant Sprague Dawley rats (n = 11-12/group) were gavaged daily with vehicle, 2.5 or 25.0 μg/kg BPA, or 5.0 or 10.0 μg/kg ethinyl estradiol (EE2) on gestational days 6-21. The BPA doses were selected to be below the no-observed-adverse-effect level (NOAEL) of 5 mg/kg/day. On postnatal days 1-21, all offspring/litter were orally treated with the same dose. A naïve control group was not gavaged. Body weight, pubertal age, estrous cyclicity, and adult serum hormone levels were measured. Adolescent play, running wheel activity, flavored solution intake, female sex behavior, and manually elicited lordosis were assessed. No significant differences existed between the vehicle and naïve control groups. Vehicle controls exhibited significant sexual dimorphism for most behaviors, indicating these evaluations were sensitive to sex differences. However, only EE2 treatment caused significant effects. Relative to female controls, EE2-treated females were heavier, exhibited delayed vaginal opening, aberrant estrous cyclicity, increased play behavior, decreased running wheel activity, and increased aggression toward the stimulus male during sexual behavior assessments. Relative to male controls, EE2-treated males were older at testes descent and preputial separation and had lower testosterone levels. These results suggest EE2-induced masculinization/defeminization of females and are consistent with increased volume of the sexually dimorphic nucleus of the preoptic area (SDN-POA) at weaning in female siblings of these subjects (He, Z., Paule, M. G. and Ferguson, S. A. (2012) Low oral doses of bisphenol A increase volume of the sexually dimorphic nucleus of the preoptic area in male, but not female, rats at postnatal day 21. Neurotoxicol. Teratol. 34, 331-337). Although EE2 treatment caused pubertal delays and decreased testosterone levels in males, their behaviors were within the range of control males. Conversely, BPA treatment did not alter any measured endpoint. Similar to our previous reports (Ferguson, S. A., Law, C. D. Jr and Abshire, J. S. (2011) Developmental treatment with bisphenol A or ethinyl estradiol causes few alterations on early preweaning measures. Toxicol. Sci. 124, 149-160; Ferguson, S. A., Law, C. D. and Abshire, J. S. (2012) Developmental treatment with bisphenol A causes few alterations on measures of postweaning activity and learning. Neurotoxicol. Teratol. 34, 598-606), the BPA doses and design used here produced few alterations.
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Affiliation(s)
- Sherry A Ferguson
- Division of Neurotoxicology, National Center for Toxicological Research/Food and Drug Administration, Jefferson, Arkansas 72079
| | - Charles Delbert Law
- Division of Neurotoxicology, National Center for Toxicological Research/Food and Drug Administration, Jefferson, Arkansas 72079
| | - Grace E Kissling
- Biostatistics Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
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Boudalia S, Berges R, Chabanet C, Folia M, Decocq L, Pasquis B, Abdennebi-Najar L, Canivenc-Lavier MC. A multi-generational study on low-dose BPA exposure in Wistar rats: effects on maternal behavior, flavor intake and development. Neurotoxicol Teratol 2013; 41:16-26. [PMID: 24269606 DOI: 10.1016/j.ntt.2013.11.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 11/01/2013] [Accepted: 11/07/2013] [Indexed: 11/16/2022]
Abstract
Bisphenol A (BPA) is a common endocrine disruptor found as an environmental and food contaminant. It exerts both developmental and behavioral effects, mainly when exposure occurs in early life. The aim of this study was to determine the multi-generational effects of chronic, human-relevant low-dose exposure to BPA on development, maternal behavior and flavor preference in Wistar rats. BPA was orally administered at a daily dose of 5 μg/kg body weight to F0 pregnant dams from the first day of gestation (GD 1) until the last day of lactation (LD 21), and then to F1 offspring from weaning (PND 21) to adulthood (PND 100). F2 offspring were not exposed. Development and clinical signs of toxicity were assessed daily. Maternal behavior was evaluated by observing nursing and pup-caring actions, as well as "non-maternal" behaviors in F0 and F1 dams from parturition until LD 8. The flavor preferences of F1 and F2 offspring were evaluated based on the intake of sweet, salt and fat solutions using the two-bottle choice test on PND 21-34 and PND 86-99. BPA exposure: 1) decreased maternal behavior in F1 dams, 2) caused developmental defects in both F1 and F2 offspring, with a noticeable decrease in anogenital distance in male rats, and 3) did not affect flavored solution intake in F1, but induced changes in sweet preference in F2 juveniles and in salt and fat solution intakes in F2 adults, and 4) induced a body weight increase in the F2 generation only, whereas food intake and water consumption did not change. Taken as a whole, our findings showed that both gestational (F0) and lifelong (F1) exposures to a human-relevant dose of BPA could induce multi-generational effects on both development and behavior. These results suggest possible selective neuroendocrine defects and/or epigenetic changes caused by BPA exposure.
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Affiliation(s)
- Sofiane Boudalia
- INRA, UMR1324, Centre des Sciences du Goût et de l'Alimentation, 21000 Dijon, France; CNRS, UMR6265, Centre des Sciences du Goût et de l'Alimentation, 21000 Dijon, France; Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, 21000 Dijon, France
| | - Raymond Berges
- INRA, UMR1324, Centre des Sciences du Goût et de l'Alimentation, 21000 Dijon, France; CNRS, UMR6265, Centre des Sciences du Goût et de l'Alimentation, 21000 Dijon, France; Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, 21000 Dijon, France
| | - Claire Chabanet
- INRA, UMR1324, Centre des Sciences du Goût et de l'Alimentation, 21000 Dijon, France; CNRS, UMR6265, Centre des Sciences du Goût et de l'Alimentation, 21000 Dijon, France; Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, 21000 Dijon, France
| | - Mireille Folia
- INRA, UMR1324, Centre des Sciences du Goût et de l'Alimentation, 21000 Dijon, France; CNRS, UMR6265, Centre des Sciences du Goût et de l'Alimentation, 21000 Dijon, France; Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, 21000 Dijon, France; Centre Hospitalier Universitaire de Dijon, 21000 Dijon, France
| | - Laurence Decocq
- INRA, UMR1324, Centre des Sciences du Goût et de l'Alimentation, 21000 Dijon, France; CNRS, UMR6265, Centre des Sciences du Goût et de l'Alimentation, 21000 Dijon, France; Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, 21000 Dijon, France
| | - Bruno Pasquis
- INRA, UMR1324, Centre des Sciences du Goût et de l'Alimentation, 21000 Dijon, France; CNRS, UMR6265, Centre des Sciences du Goût et de l'Alimentation, 21000 Dijon, France; Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, 21000 Dijon, France
| | | | - Marie-Chantal Canivenc-Lavier
- INRA, UMR1324, Centre des Sciences du Goût et de l'Alimentation, 21000 Dijon, France; CNRS, UMR6265, Centre des Sciences du Goût et de l'Alimentation, 21000 Dijon, France; Université de Bourgogne, Centre des Sciences du Goût et de l'Alimentation, 21000 Dijon, France.
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Ferguson SA, Law CD, Abshire JS. Developmental treatment with bisphenol A causes few alterations on measures of postweaning activity and learning. Neurotoxicol Teratol 2012; 34:598-606. [DOI: 10.1016/j.ntt.2012.09.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 09/19/2012] [Accepted: 09/19/2012] [Indexed: 01/13/2023]
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12
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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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Ferguson SA, Boctor SY. Cocaine responsiveness or anhedonia in rats treated with methylphenidate during adolescence. Neurotoxicol Teratol 2010; 32:432-42. [PMID: 20347964 DOI: 10.1016/j.ntt.2010.03.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Revised: 03/16/2010] [Accepted: 03/21/2010] [Indexed: 02/06/2023]
Abstract
Methylphenidate (MPH) treatment in boys diagnosed with ADHD is reported to decrease the risk of drug abuse in adulthood. Similarly, MPH treatment appears to decrease the cocaine preference of male rats during conditioned place preference (CPP) tests. However, the effects of MPH treatment on later drug use of girls/women or CPP in female rodents have not been fully examined, nor have a clinically-relevant MPH dose and/or administration route been thoroughly studied. Here, Sprague-Dawley rats (n=34/sex/treatment) were treated orally 3x/day on postnatal days (PNDs) 29-50 with water or 3mg MPH/kg, a dose producing serum levels within the human clinical range. CPP assessments to cocaine (10 mg/kg, ip) (PNDs 62-71) indicated MPH-treated rats were less active during pre- and postconditioning sessions (p<.04), but there were no significant MPH-related differences in conditioning strength. Baseline open field activity at PND 84 indicated that MPH-treated females were more active than same-sex controls (p<.05). A cocaine challenge (10 mg/kg, ip) elevated activity similarly in MPH-treated and controls of both sexes. As an anhedonia measure, saccharin solution intake on PNDs 87-90 indicated no significant MPH effects. Estrous cycle phase did not appear to affect cocaine response during CPP or open field assessments. Hormonal levels at PND 90 indicated 63% higher corticosterone levels in MPH-treated females relative to same-sex controls (p<.05), a finding that deserves further investigation. These results address some of the major issues surrounding animal models of MPH treatment and provide additional support for a lack of severe long-term behavioral effects of adolescent MPH.
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Affiliation(s)
- Sherry A Ferguson
- Division of Neurotoxicology, National Center for Toxicological Research/FDA, Jefferson, AR 72079, United States.
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Ferguson SA, Delclos KB, Newbold RR, Flynn KM. Few effects of multi-generational dietary exposure to genistein or nonylphenol on sodium solution intake in male and female Sprague–Dawley rats. Neurotoxicol Teratol 2009; 31:143-8. [PMID: 19452615 DOI: 10.1016/j.ntt.2009.01.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Della Seta D, Farabollini F, Dessì-Fulgheri F, Fusani L. Environmental-like exposure to low levels of estrogen affects sexual behavior and physiology of female rats. Endocrinology 2008; 149:5592-8. [PMID: 18635664 DOI: 10.1210/en.2008-0113] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Xenoestrogens are endocrine-disrupting chemicals that mimic the action of endogenous estrogen hormones. Effects of xenoestrogen on aquatic wildlife are well documented, whereas the experimental evidence for impairment of reproductive behavior and physiology in mammals after exposure to xenoestrogens has been debated. The strongest arguments against such studies have been that the route, time course, and intensity of exposure did not simulate environmental exposure and that the chemicals tested have additional nonestrogenic toxic effects, hindering generalization of actual xenoestrogenic effects. Here we show that environmental-like exposure to the pure estrogen 17alpha-ethinylestradiol during development alters reproductive behavior and physiology in adult female Sprague-Dawley rats. We simulated environmental exposure by giving low doses (0.4 and 0.004 microg/kg.d) of 17alpha-ethinylestradiol orally to pregnant females from conception to weaning of the pups, which continued to receive the treatment until puberty. We studied the sexual behavior, estrous cycle, and estradiol plasma levels of intact female rats when they reached 3 months of age. Exposure to the higher dose strongly affected female sexual behavior and physiology, with suppression of lordosis and the estrous cycle and enhanced aggression toward males. The lower dose disrupted appetitive components of sexual behavior that influence the rate of copulation. Estradiol plasma levels were not affected by the treatment. Our study revealed that exposure to low oral doses of a pure estrogen during development alters female sexual behavior and physiology. These results suggest potential risks of reproductive failure from xenoestrogen exposure in realistic ecological conditions.
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Vosges M, Braguer JC, Combarnous Y. Long-term exposure of male rats to low-dose ethinylestradiol (EE2) in drinking water: Effects on ponderal growth and on litter size of their progeny. Reprod Toxicol 2008; 25:161-8. [DOI: 10.1016/j.reprotox.2007.12.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2007] [Revised: 10/30/2007] [Accepted: 12/13/2007] [Indexed: 11/26/2022]
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17
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Howdeshell KL, Furr J, Lambright CR, Wilson VS, Ryan BC, Gray LE. Gestational and Lactational Exposure to Ethinyl Estradiol, but not Bisphenol A, Decreases Androgen-Dependent Reproductive Organ Weights and Epididymal Sperm Abundance in the Male Long Evans Hooded Rat. Toxicol Sci 2007; 102:371-82. [DOI: 10.1093/toxsci/kfm306] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Della Seta D, Minder I, Belloni V, Aloisi AM, Dessì-Fulgheri F, Farabollini F. Pubertal exposure to estrogenic chemicals affects behavior in juvenile and adult male rats. Horm Behav 2006; 50:301-7. [PMID: 16716326 DOI: 10.1016/j.yhbeh.2006.03.015] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2005] [Revised: 03/31/2006] [Accepted: 03/31/2006] [Indexed: 10/24/2022]
Abstract
In this paper, we tested the hypothesis that exposure to estrogens of different source and estrogenic potency at early puberty could affect the development of socio-sexual behavior in the male rat. Puberty is regarded as a second stage of the ontogenetic period, in the sexual maturation of mammals, particularly sensitive to gonadal hormone milieu. We treated animals orally, from postnatal day 23 to 30, with an environmentally compatible dose of bisphenol A (BPA, 40 microg/kg/day) and with a dosage of ethinylestradiol (EE, 0.4 microg/kg/day) comparable to the human oral contraceptives. Exposure to EE altered the temporal pattern of male sexual activity, reducing performance, in the adult animals; slight modifications, in the same direction, were observed with BPA. Short-term behavioral effects were observed in the treated animals, both with BPA and EE: the exploratory drive, directed to a stimulus object and to the environment, as well as to conspecifics, was reduced in the juveniles. Modifications in the circulating T levels were observed after treatments: T was reduced in the juveniles, both with BPA and EE. The decrement persisted in the adult animals but reached significance only in the BPA group. On the whole, effects of pubertal exposure on behavior are more marked with EE than BPA. This can be due to the much higher estrogenic potency of EE; the direction of the behavioral effects of BPA, compared with EE, is however indicative of an estrogenic mechanism.
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Affiliation(s)
- Daniele Della Seta
- Department of Physiology, Section of Neuroscience and Applied Physiology, University of Siena, 53100 Siena, Italy.
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Guo TL, Germolec DR, Musgrove DL, Delclos KB, Newbold RR, Weis C, White KL. Myelotoxicity in genistein-, nonylphenol-, methoxychlor-, vinclozolin- or ethinyl estradiol-exposed F1 generations of Sprague–Dawley rats following developmental and adult exposures. Toxicology 2005; 211:207-19. [PMID: 15925024 DOI: 10.1016/j.tox.2005.03.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2004] [Revised: 01/13/2005] [Accepted: 03/16/2005] [Indexed: 11/18/2022]
Abstract
The myelotoxicity of five endocrine active chemicals was evaluated in F1 generation of Sprague-Dawley rats following developmental and adult exposures at three concentration levels. Rats were exposed to genistein (GEN: 25, 250 and 1250 ppm), nonylphenol (NPH: 25, 500 and 2000 ppm), methoxychlor (MXC: 10, 100 and 1000 ppm), vinclozolin (VCZ: 10, 150 and 750 ppm) and ethinyl estradiol (EE2: 5, 25 and 200 ppb) gestationally and lactationally through dams from day 7 of gestation and through feed after weaning on postnatal day (PND) 22 to PND 64. The parameters examined included the number of recovered bone marrow cells, DNA synthesis, and colony forming units (CFU) in the presence of granulocyte macrophage-colony stimulating factor (GM-CSF), macrophage colony-stimulating factor (M-CSF) and erythropoietin. Except for the EE2, the concentrations of other individual chemicals in the diet were in an approximate range that allowed for a comparison to be made in terms of myelotoxic potency. Decreases in the DNA synthesis, CFU-GM and CFU-M seemed to be the common findings among the alterations induced by these compounds. Using the numbers of alterations induced by each chemical in the parameters examined as criteria for comparison, the order of myelotoxic potency in F(1) males was: GEN>MXC>NPH>VCZ; the order in females: GEN>NPH>VCZ. Additionally, some of the functional changes induced by these compounds were gender-specific or dimorphic. Overall, the results demonstrated that developmental and adult exposures of F1 rats to these endocrine active chemicals at the concentrations tested had varied degrees of myelotoxicity with GEN being the most potent. Furthermore, the sex-specific effects of these chemicals in F1 male and female rats suggest that there may be interactions between these compounds and sex hormone in modulating these responses.
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Affiliation(s)
- T L Guo
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, P.O. Box 980613, Richmond, VA 23298-0613, USA.
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20
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Lephart ED, Setchell KDR, Handa RJ, Lund TD. Behavioral effects of endocrine-disrupting substances: phytoestrogens. ILAR J 2005; 45:443-54. [PMID: 15454683 DOI: 10.1093/ilar.45.4.443] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A major source of endocrine-disrupting substances, usually not considered in laboratory animal experiments, is the diet used in research investigations. Soy represents the main protein source in almost all natural-ingredient commercially available formulated diets. Soy-derived isoflavones are the most abundant and in many ways the most studied phytoestrogens, and phytoestrogens (isoflavones) are known endocrine disruptors. Research is reviewed that identifies the physiological and behavioral endocrine-disrupting effects of dietary phytoestrogens (isoflavones) in animal diets, including most of the isoflavones, which are in a glycoside form and biologically inactive, and those in the gastrointestinal tract, which are biologically active. The isoflavones genistein and daidzein have similar molecular weights and structural characteristics to that of 17-beta estradiol, which may enable them to exert estrogenic and antiestrogenic properties are described and characterized. Daidzein can be further metabolized to the potent and abundant molecule equol, which in rodents is produced in very large amounts and represents the major circulating metabolite among all biologically active isoflavones. Equol has the unique and important ability to specifically bind 5 alpha-dihydro-testosterone, and to act in turn to inhibit the action of this potent androgen. The specific influence of dietary soy phytoestrogens on consumptive, learning and memory, and anxiety-related behaviors is identified. Regulatory behaviors such as food and water intake, adipose deposition and leptin, and insulin levels affected by dietary isoflavones are also discussed.
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Affiliation(s)
- Edwin D Lephart
- Department of Physiology and Developmental Biology, Neuroscience Center, Brigham Young University, Provo, UT, USA
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Flynn KM, Delclos KB, Newbold RR, Ferguson SA. Long term dietary methoxychlor exposure in rats increases sodium solution consumption but has few effects on other sexually dimorphic behaviors. Food Chem Toxicol 2005; 43:1345-54. [PMID: 15989973 DOI: 10.1016/j.fct.2005.03.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2004] [Revised: 03/03/2005] [Accepted: 03/11/2005] [Indexed: 11/18/2022]
Abstract
Methoxychlor is an insecticide with estrogen-like activity, thus exposure during development might cause sexually dimorphic behavioral alterations. To evaluate this, pregnant rats consumed diets containing 0, 10, 100 or 1000 ppm methoxychlor from gestational day 7, and offspring continued on these diets until postnatal day (PND) 77. Assessments of sexually dimorphic behaviors in offspring indicated that intake of a 3.0% sodium chloride solution was significantly increased (41%) in males and females of the 1000 ppm group. No treatment group differed from controls in open field nor running wheel activity, play behavior, nor 0.3% saccharin solution intake. Offspring of the 1000 ppm group showed significantly decreased body weight, reaching 17% less than controls at PND 77, but not clearly related to their salt solution intake. During pregnancy, 1000 ppm dams consumed 23% less food and weighed 10% less than controls, but this did not affect litter outcomes. These results indicate that in rodents, developmental and chronic exposure to dietary methoxychlor alters the sexually dimorphic behavior of salt-solution intake in young adults of both sexes. Similar behavioral alterations with other xenoestrogens, and the potential for interactions among xenoestrogens, suggest that this report may minimize the true effects of dietary methoxychlor exposure.
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Affiliation(s)
- K M Flynn
- Division of Neurotoxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR 72079, USA.
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Shibutani M, Masutomi N, Uneyama C, Abe N, Takagi H, Lee KY, Hirose M. Down-regulation of GAT-1 mRNA expression in the microdissected hypothalamic medial preoptic area of rat offspring exposed maternally to ethinylestradiol. Toxicology 2005; 208:35-48. [PMID: 15664431 DOI: 10.1016/j.tox.2004.11.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2004] [Revised: 11/04/2004] [Accepted: 11/04/2004] [Indexed: 11/16/2022]
Abstract
Steroid hormones are powerful regulators of gene transcription in the brain and have the potential to permanently alter the structure and function of the developing brain. Steroid-mediated altered gene expression may thus be responsible for the molecular cascade for sexual differentiation. In this study, to assess effects of maternal exposure to ethinylestradiol (EE) on brain sexual differentiation of offspring, region-specific mRNA expression of two estrogen-responsive genes, gamma-aminobutyric acid transporter type 1 (GAT-1) and anti-apoptotic bcl-xL was measured in the medial preoptic area (MPOA), including sexually dimorphic nucleus (SDN), at the late stage of brain sexual differentiation in rats. Pregnant Sprague-Dawley animals were fed diets containing EE at concentrations of 0, 0.02, 0.1, and 0.5 ppm from day 15 of pregnancy to day 9 after delivery. In another group, neonates were directly injected with estradiol benzoate (EB: 10 microg/pup, sc) on postnatal day (PND) 2. The MPOA on PND 9 was microdissected from methacarn-fixed paraffin-embedded brain sections to measure mRNA levels by competitive RT-PCR, followed by plate hybridization. EE-exposure decreased GAT-1 expression dose-dependently from 0.02 ppm in females and at 0.5 ppm in males, while EB-treatment caused reduction only in females. EE-exposure did not alter Bcl-xL levels. At week 11, EE-exposed females exhibited a similar spectrum of histopathological changes in endocrine-linked organs as with EB, evident from 0.1 ppm, while in males EE-exposure did not cause histopathological alteration despite clear change with EB-treatment. Measurement of SDN-POA dimensions at week 11 revealed volume reduction in males exposed to 0.5 ppm EE or EB. The results suggest that GAT-1 expression in the developing MPOA is a sensitive measure for the level of disruption of brain sexual differentiation due to maternal dietary exposure to estrogens, despite definite reproductive abnormalities may not be detectable in males with this exposure protocol.
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Affiliation(s)
- Makoto Shibutani
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
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Zoeller RT, Bansal R, Parris C. Bisphenol-A, an environmental contaminant that acts as a thyroid hormone receptor antagonist in vitro, increases serum thyroxine, and alters RC3/neurogranin expression in the developing rat brain. Endocrinology 2005; 146:607-12. [PMID: 15498886 DOI: 10.1210/en.2004-1018] [Citation(s) in RCA: 322] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Considering the importance of thyroid hormone (TH) in brain development, it is of potential concern that a wide variety of environmental chemicals can interfere with thyroid function or, perhaps of greater concern, with TH action at its receptor (TR). Recently bisphenol-A (BPA, 4,4' isopropylidenediphenol) was reported to bind to the rat TR and act as an antagonist in vitro. BPA is a high production volume chemical, with more than 800 million kg of BPA produced annually in the United States alone. It is detectable in serum of pregnant women and cord serum taken at birth; is 5-fold higher in amniotic fluid at 15-18 wk gestation, compared with maternal serum; and was found in concentrations of up to 100 ng/g in placenta. Thus, the human population is widely exposed to BPA and it appears to accumulate in the fetus. We now report that dietary exposure to BPA of Sprague Dawley rats during pregnancy and lactation causes an increase in serum total T4 in pups on postnatal d 15, but serum TSH was not different from controls. The expression of the TH-responsive gene RC3/neurogranin, measured by in situ hybridization, was significantly up-regulated by BPA in the dentate gyrus. These findings suggest that BPA acts as a TH antagonist on the beta-TR, which mediates the negative feedback effect of TH on the pituitary gland, but that BPA is less effective at antagonizing TH on the alpha-TR, leaving TRalpha-mediated events to respond to elevated T4.
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Affiliation(s)
- R Thomas Zoeller
- Biology Department, Morrill Science Center, University of Massachusetts, Amherst, Massachusetts 01003, USA.
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Sandner G, Silva RCB, Angst MJ, Knobloch J, Danion JM. Prenatal exposure of Long-Evans rats to 17alpha-ethinylestradiol modifies neither latent inhibition nor prepulse inhibition of the startle reflex but elicits minor deficits in exploratory behavior. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 2004; 152:177-87. [PMID: 15351506 DOI: 10.1016/j.devbrainres.2004.06.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/25/2004] [Indexed: 11/23/2022]
Abstract
Prenatal administration of synthetic estrogens in humans as well as lower mammals was reported to alter behavior in adulthood. The alterations remain to be characterized according to specific pathophysiological hypotheses. In this study, three common behavioral models of schizophrenia were tested, i.e., latent inhibition (LI), prepulse inhibition of the startle response (PPI) and hyperlocomotion under amphetamine. Female Long-Evans rats were injected i.p. with a solution of 17alpha-ethinylestradiol (15 microg kg(-1)) everyday from day 9 to 14 of pregnancy, and behavioral characteristics of their offspring, raised by Wistar foster mothers, were compared to those of rats born from dams injected with the vehicle only, over the same gestation period. LI was tested in a conditioned taste aversion and a conditioned passive avoidance paradigm followed by a parametric study of PPI and an evaluation of locomotion in an open field under saline or amphetamine (1.5 mg kg(-1)). Histological brain measurements were also carried out in a subset of the same rats. Neither LI nor PPI was altered using methods that had proven sensitive in previous pharmacological studies. Treated rats' locomotion was impaired, but amphetamine did not elicit a differential enhancement. A thinner Amon's horn layer was observed in their hippocampus. This indicates that standard models of schizophrenia did not fit to the behavioral abnormalities found by others and confirmed in this study. They were not due to the abnormal maternal care to pups elicited by the treatment.
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Affiliation(s)
- Guy Sandner
- U405 INSERM, Faculty of Medicine, Louis Pasteur University, 11 rue Humann, 67085 Strasbourg Cédex, France.
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