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Zaccaroni M, Massolo A, Beani L, Seta DD, Farabollini F, Giannelli G, Fusani L, Dessì-Fulgheri F. Developmental exposure to low levels of ethinylestradiol affects social play in juvenile male rats. Toxicol Res 2020; 36:301-310. [PMID: 33005589 DOI: 10.1007/s43188-019-00035-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 10/21/2019] [Accepted: 11/27/2019] [Indexed: 11/29/2022] Open
Abstract
Juvenile social play contributes to the development of adult social and emotional skills in humans and non-human animals and is therefore a useful endpoint to study the effects of endocrine disrupters on behavior in animal models. Ethinylestradiol (EE2), a widely produced, powerful synthetic estrogen is widespread in the environment mainly because it is a component of the contraceptive pill. To understand whether clinical or environmental exposure to EE2 during critical perinatal periods can affect male social play, we exposed 72 male Sprague-Dawley rats to EE2 or vehicle either during gestation (from gestation day (GD) 5 through 20) or during lactation (from postnatal day (PND) 1 through 21). Two doses of EE2 were used to treat the dams: a lower dose in the range of possible environmental exposure (4 ng/kg/day) and a higher dose similar to that received during contraceptive treatment (400 ng/kg/day). Social play was observed between PND 40 and 45. A principal component analysis (PCA) of frequencies of behavioral items observed during play sessions allowed to allocate behaviors to the two main components that we named aggressive-like play and defensive-like play. Aggressive-like play was increased by gestational and decreased by lactational exposure. Defensive-like play was decreased by treatment. For both types of play the lower dose (4 ng/kg/day) was as effective as the higher one. Total social activity was increased by gestational and decreased by lactational exposure. These findings provide further evidence that exposure to low and to very low doses of EE2 during critical periods of development can affect essential aspects of social behavior, and that the timing of exposure is critical to understand its developmental action.
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Affiliation(s)
- Marco Zaccaroni
- Department di Biology, University of Firenze, Florence, Italy
| | - Alessandro Massolo
- Ethology Unit, Department of Biology, University of Pisa, Pisa, Italy and Laboratoire Chrono-environnement, Université Bourgogne Franche-Comté, Besançon, France
| | - Laura Beani
- Department di Biology, University of Firenze, Florence, Italy
| | - Daniele Della Seta
- Department of Medicine, Surgery and Neuroscience University of Siena, Siena, Italy
| | | | | | - Leonida Fusani
- Department of Cognitive Biology, University of Vienna, and Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Austria
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2
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Lin PH, Kuo TH, Chen CC, Jian CY, Chen CW, Wang KL, Kuo YC, Shen HY, Hsia SM, Wang PS, Lieu FK, Wang SW. Downregulation of testosterone production through luteinizing hormone receptor regulation in male rats exposed to 17α-ethynylestradiol. Sci Rep 2020; 10:1576. [PMID: 32005928 PMCID: PMC6994641 DOI: 10.1038/s41598-020-58125-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 01/03/2020] [Indexed: 11/09/2022] Open
Abstract
The pharmaceutical 17α-ethynylestradiol (EE2) is considered as an endocrine-disrupting chemical that interferes with male reproduction and hormonal activation. In this study, we investigated the molecular mechanism underlying EE2-regulatory testosterone release in vitro and in vivo. The results show that EE2 treatment decreased testosterone release from rat Leydig cells. Treatment of rats with EE2 reduced plasma testosterone levels and decreased the sensitivity of human chorionic gonadotropin (hCG). EE2 reduced luteinizing hormone receptor (LHR) expression associated with decreased cAMP generation by downregulation of adenylyl cyclase activity and decreased intracellular calcium-mediated pathways. The expression levels of StAR and P450scc were decreased in Leydig cells by treatment of rats with EE2 for 7 days. The sperm motility in the vas deferens and epididymis was reduced, but the histopathological features of the testis and the total sperm number of the vas deferens were not affected. Moreover, the serum dihydrotestosterone (DHT) level was decreased by treatment with EE2. The prostate gland and seminal vesicle atrophied significantly, and their expression level of 5α-reductase type II was reduced after EE2 exposure. Taken together, these results demonstrate an underlying mechanism of EE2 to downregulate testosterone production in Leydig cells, explaining the damaging effects of EE2 on male reproduction.
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Affiliation(s)
- Po-Han Lin
- Institute and Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan.,School of Nutrition and Health Sciences, College of Nutrition, Taipei Medical University, Taipei, 11031, Taiwan.,Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan
| | - Tsung-Hsien Kuo
- Institute and Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan
| | - Chih-Chieh Chen
- Institute and Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan.,Department of Nutrition, China Medical University, Taichung, 40402, Taiwan
| | - Cai-Yun Jian
- Institute and Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan
| | - Chien-Wei Chen
- Institute and Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan.,College of Human Development and Health, National Taipei University of Nursing and Health Sciences, Taipei, 11219, Taiwan
| | - Kai-Lee Wang
- Institute and Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan.,Department of Nursing, Ching Kuo Institute of Management and Health, Keelung, 20301, Taiwan
| | - Yuh-Chen Kuo
- Department of Urology, Yangming Branch of Taipei City Hospital, Taipei, 11146, Taiwan
| | - Heng-Yi Shen
- Department of Rehabilitation, Cheng Hsin General Hospital, Taipei, 11212, Taiwan
| | - Shih-Min Hsia
- School of Nutrition and Health Sciences, College of Nutrition, Taipei Medical University, Taipei, 11031, Taiwan.,Graduate Institute of Metabolism and Obesity Sciences, College of Nutrition, Taipei Medical University, Taipei, 11031, Taiwan
| | - Paulus S Wang
- Institute and Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, 11221, Taiwan. .,Medical Center of Aging Research, China Medical University Hospital, Taichung, 40402, Taiwan. .,Department of Biotechnology, College of Health Science, Asia University, Taichung, 41354, Taiwan. .,Department of Medical Research, Taipei Veterans General Hospital, Taipei, 11217, Taiwan.
| | - Fu-Kong Lieu
- Department of Rehabilitation, Cheng Hsin General Hospital, Taipei, 11212, Taiwan. .,Department of Physical Medicine and Rehabilitation, National Defense Medical Center, Taipei, 11490, Taiwan.
| | - Shyi-Wu Wang
- Aesthetic Medical Center, Department of Dermatology, Chang Gung Memorial Hospital, Taoyuan, 33378, Taiwan. .,Department of Physiology and Pharmacology, College of Medicine, Chang Gung University, Taoyuan, 33302, Taiwan.
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3
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Zaccaroni M, Massolo A, Della Seta D, Farabollini F, Giannelli G, Fusani L, Dessì-Fulgheri F. Developmental Exposure to Low Levels of Ethinylestradiol Affects Play Behavior in Juvenile Female Rats. Neurotox Res 2017; 33:876-886. [PMID: 29260494 DOI: 10.1007/s12640-017-9852-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 12/10/2017] [Accepted: 12/11/2017] [Indexed: 10/18/2022]
Abstract
Juvenile social play contributes to the development of adult social and emotional skills in humans and non-human animals, and is therefore a useful endpoint to study the effects of endocrine disrupters on behavior in animal models. Ethinylestradiol (EE2) is a widely produced, powerful synthetic estrogen that is widespread in the environment mainly because is a component of the contraceptive pill. In addition, fetuses may be exposed to EE2 when pregnancy is undetected during contraceptive treatment. To understand whether exposure to EE2 during gestation or lactation affects social play, we exposed 72 female Sprague-Dawley rats to EE2 or vehicle either during gestation (gestation day (GD) 5 through GD 20) or during lactation (from postnatal day (PND) 1 through PND 21). Two doses of EE2 were used to treat the dams: a lower dose in the range of possible environmental exposure (4 ng/kg/day) and a higher dose equivalent to that received during contraceptive treatment (400 ng/kg/day). Behavioral testing was carried out between PND 40 and 45. A principal component analysis of frequencies of behavioral items observed during play sessions identified three main components: defensive-like play, aggressive-like play, and exploration. Aggressive-like play was significantly increased by both doses of EE2, and the gestational administration was in general more effective than the lactational one. Defensive-like play and exploration were not significantly affected by treatment. This research showed that low and very low doses of EE2 that mimic clinical or environmental exposure during development can affect important aspects of social behavior even during restricted time windows.
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Affiliation(s)
- Marco Zaccaroni
- Department di Biology, University of Firenze, Florence, Italy.
| | - Alessandro Massolo
- Ethology Unit, Department of Biology, University of Pisa, Pisa, Italy.,Laboratoire Chrono-environnement, Université Bourgogne Franche-Comté, Besançon, France
| | - Daniele Della Seta
- Department of Medicine, Surgery and Neuroscience University of Siena, Siena, Italy
| | | | | | - Leonida Fusani
- Department of Cognitive Biology, University of Vienna, and Konrad Lorenz Institute for Ethology, University of Veterinary Medicine, Vienna, Austria
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4
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Zhang H, Taya K, Nagaoka K, Yoshida M, Watanabe G. Neonatal exposure to 17α-ethynyl estradiol (EE) disrupts follicle development and reproductive hormone profiles in female rats. Toxicol Lett 2017; 276:92-99. [DOI: 10.1016/j.toxlet.2017.05.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 04/14/2017] [Accepted: 05/12/2017] [Indexed: 01/23/2023]
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Takahashi M, Ichimura R, Inoue K, Morikawa T, Kuwata K, Watanabe G, Yoshida M. The role of estrogen receptor subtypes for induction of delayed effects on the estrous cycle and female reproductive organs in rats. Reprod Biol 2017; 17:111-119. [PMID: 28215489 DOI: 10.1016/j.repbio.2017.01.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 01/06/2017] [Accepted: 01/31/2017] [Indexed: 11/24/2022]
Abstract
It has been reported that neonatal exposure to estrogens at relatively low doses can induce early onset anovulation as a delayed effect in female rats. Dysfunction of kisspeptin neurons in the anteroventral periventricular nucleus (AVPV) was proposed to be a trigger for this effect. To determine the roles of estrogen receptor (ER) subtypes in the induction of delayed effects, we conducted a series of experiments using Donryu rats to examine whether neonatal injection of an ERα agonist (PPT), an ERβ agonist (DPN) or an ERα antagonist (ICI) could induce delayed effects. Also, involvement of the kisspeptin neurons in the AVPV for induction of delayed effect by PPT and DPN was investigated. We observed that neonatal exposure to PPT, DPN and ICI induced the early onset of abnormal estrous cyclicity after sexual maturation, suggesting that the compounds capable of inducing delayed effects are not limited to ERα agonists. On the other hand, the data suggested the possibility that DPN and ICI functioned partially as ERα agonists in the neonatal brain. Regardless of the agents used, there is a possibility that dysfunction of kisspeptin neurons in the AVPV might contribute to induction of early onset anovulation.
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Affiliation(s)
- Miwa Takahashi
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
| | - Ryohei Ichimura
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan; Laboratory of Veterinary Physiology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
| | - Kaoru Inoue
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
| | - Tomomi Morikawa
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
| | - Kazunori Kuwata
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan; Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, 12 Fuchu-shi, Tokyo 183-8509, Japan
| | - Gen Watanabe
- Laboratory of Veterinary Physiology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
| | - Midori Yoshida
- Food Safety Commission, Akasaka Park Bld. 22nd F. Akasaka 5-2-20, Minato-ku, Tokyo 107-6122, Japan.
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6
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Komine C, Nakajima S, Kondo Y, Horii Y, Yoshida M, Kawaguchi M. Effects of neonatal 17α-ethinyloestradiol exposure on female-paced mating behaviour in the rat. J Appl Toxicol 2017; 37:996-1003. [PMID: 28176338 DOI: 10.1002/jat.3449] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 01/05/2017] [Accepted: 01/05/2017] [Indexed: 12/20/2022]
Abstract
Correct perinatal oestrogen levels are critical for sexual differentiation. For example, perinatal exposure to oestrogen causes masculinization and defeminization of the brain in female rats and also induces delayed effects after maturation characterized by early onset of abnormal oestrus cycling. However, the mechanisms underlying the above effects of oestrogen remain to be fully determined. 17α-ethinyloestradiol (EE), a common synthetic oestrogen widely used in oral contraceptives, binds specifically to oestrogen receptors. In this study, we demonstrated the effects of a single neonatal injection of high- or low-dose EE on reproductive behaviours. Female rats within 24 h after birth were subcutaneously injected with sesame oil, EE (0.02, 2 mg kg-1 ) and 17β-oestradiol (E2 ) (20 mg kg-1 ). Between 11 and 15 weeks of age, sexual behaviour was tested twice in a paced mating situation. Latency to enter, lordosis and soliciting behaviour were recorded. Both high-dose EE- and E2 -treated females showed a significantly lower lordosis quotient, decreased soliciting behaviours, increased rejection and fighting numbers. Accessibility to males was also delayed by neonatal E2 exposure, although it was shortened by high-dose EE exposure. In contrast, low-dose EE-treated females did not exhibit impaired sexual behaviour. These results suggest that single neonatal exposure to a high dose of EE or E2 disturbs the normal development of the female brain, resulting in impaired sexual behaviours in a female-paced mating situation. Besides, the differences noted between high-dose EE- and E2 -treated females might be caused by different affinities of the oestrogen receptors, metabolic rates or mechanisms of action. Copyright © 2017 John Wiley & Sons, Ltd.
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Affiliation(s)
- Chiaki Komine
- Laboratory of Animal Behavior and Environmental Science, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan
| | - Shingo Nakajima
- Laboratory of Animal Behavior and Environmental Science, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan
| | - Yasuhiko Kondo
- Department of Animal Sciences, Teikyo University of Science, 2-2-1 Senju-Sakuragi, Adachi-ku, Tokyo, Japan
| | - Yasuyuki Horii
- Laboratory of Animal Behavior and Environmental Science, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan
| | - Midori Yoshida
- National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo, Japan
| | - Maiko Kawaguchi
- Laboratory of Animal Behavior and Environmental Science, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan
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7
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Ichimura R, Takahashi M, Morikawa T, Inoue K, Kuwata K, Usuda K, Yokosuka M, Watanabe G, Yoshida M. Neonatal exposure to SERMs disrupts neuroendocrine development and postnatal reproductive function through alteration of hypothalamic kisspeptin neurons in female rats. Neurotoxicology 2016; 56:64-75. [DOI: 10.1016/j.neuro.2016.07.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 07/05/2016] [Accepted: 07/05/2016] [Indexed: 10/21/2022]
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8
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Zaccaroni M, Seta DD, Farabollini F, Fusani L, Dessì-Fulgheri F. Developmental Exposure to Very Low Levels of Ethynilestradiol Affects Anxiety in a Novelty Place Preference Test of Juvenile Rats. Neurotox Res 2016; 30:553-562. [DOI: 10.1007/s12640-016-9645-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 06/17/2016] [Accepted: 06/20/2016] [Indexed: 11/24/2022]
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9
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Takahashi M, Ichimura R, Inoue K, Morikawa T, Watanabe G, Yoshida M. The impact of neonatal exposure to 17alpha-ethynylestradiol on the development of kisspeptin neurons in female rats. Reprod Toxicol 2016; 60:33-8. [PMID: 26820455 DOI: 10.1016/j.reprotox.2016.01.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 01/12/2016] [Accepted: 01/22/2016] [Indexed: 11/25/2022]
Abstract
Neonatal exposure to 17alpha-ethynylestradiol (EE) at relatively low doses leads to delayed effects characterized by the early onset of age-related anovulation. Kisspeptin neurons in the anteroventral periventricular nucleus (AVPV), located at the anterior hypothalamus, are proposed to play key roles in appearance of these delayed effects after maturation. To understand the initial changes, we investigated Kiss1 mRNA expression in the anterior and posterior hypothalamus before weaning in female rats that received neonatal exposure to EE at various doses (0.002-2000μg/kg). The level of Kiss1 mRNA in the anterior hypothalamus was decreased from 0.002μg/kg which did not induce delayed effects. In the posterior hypothalamus, Kiss1 mRNA expression did not differ among the groups except 2000μg/kg group. These results suggest that neonatal exposure to EE affects the development of kisspeptin neurons and kisspeptin neurons in the AVPV are highly susceptible to neonatal EE treatment.
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Affiliation(s)
- Miwa Takahashi
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
| | - Ryohei Ichimura
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan; Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
| | - Kaoru Inoue
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
| | - Tomomi Morikawa
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
| | - Gen Watanabe
- Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
| | - Midori Yoshida
- Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
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Derouiche L, Keller M, Martini M, Duittoz AH, Pillon D. Developmental Exposure to Ethinylestradiol Affects Reproductive Physiology, the GnRH Neuroendocrine Network and Behaviors in Female Mouse. Front Neurosci 2015; 9:463. [PMID: 26696819 PMCID: PMC4673314 DOI: 10.3389/fnins.2015.00463] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 11/23/2015] [Indexed: 01/10/2023] Open
Abstract
During development, environmental estrogens are able to induce an estrogen mimetic action that may interfere with endocrine and neuroendocrine systems. The present study investigated the effects on the reproductive function in female mice following developmental exposure to pharmaceutical ethinylestradiol (EE2), the most widespread and potent synthetic steroid present in aquatic environments. EE2 was administrated in drinking water at environmentally relevant (ENVIR) or pharmacological (PHARMACO) doses [0.1 and 1 μg/kg (body weight)/day respectively], from embryonic day 10 until postnatal day 40. Our results show that both groups of EE2-exposed females had advanced vaginal opening and shorter estrus cycles, but a normal fertility rate compared to CONTROL females. The hypothalamic population of GnRH neurons was affected by EE2 exposure with a significant increase in the number of perikarya in the preoptic area of the PHARMACO group and a modification in their distribution in the ENVIR group, both associated with a marked decrease in GnRH fibers immunoreactivity in the median eminence. In EE2-exposed females, behavioral tests highlighted a disturbed maternal behavior, a higher lordosis response, a lack of discrimination between gonad-intact and castrated males in sexually experienced females, and an increased anxiety-related behavior. Altogether, these results put emphasis on the high sensitivity of sexually dimorphic behaviors and neuroendocrine circuits to disruptive effects of EDCs.
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Affiliation(s)
- Lyes Derouiche
- PRC, UMR 7247 INRA/CNRS/Université François-Rabelais de Tours/IFCE Nouzilly, France
| | - Matthieu Keller
- PRC, UMR 7247 INRA/CNRS/Université François-Rabelais de Tours/IFCE Nouzilly, France
| | - Mariangela Martini
- PRC, UMR 7247 INRA/CNRS/Université François-Rabelais de Tours/IFCE Nouzilly, France
| | - Anne H Duittoz
- PRC, UMR 7247 INRA/CNRS/Université François-Rabelais de Tours/IFCE Nouzilly, France
| | - Delphine Pillon
- PRC, UMR 7247 INRA/CNRS/Université François-Rabelais de Tours/IFCE Nouzilly, France
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Ichimura R, Takahashi M, Morikawa T, Inoue K, Kuwata K, Usuda K, Yokosuka M, Watanabe G, Yoshida M. The Critical Hormone-Sensitive Window for the Development of Delayed Effects Extends to 10 Days after Birth in Female Rats Postnatally Exposed to 17alpha-Ethynylestradiol1. Biol Reprod 2015; 93:32. [DOI: 10.1095/biolreprod.115.129650] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 06/25/2015] [Indexed: 11/01/2022] Open
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12
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Prior attenuation of KiSS1/GPR54 signaling in the anteroventral periventricular nucleus is a trigger for the delayed effect induced by neonatal exposure to 17alpha-ethynylestradiol in female rats. Reprod Toxicol 2015; 51:145-56. [PMID: 25615539 DOI: 10.1016/j.reprotox.2015.01.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 12/25/2014] [Accepted: 01/10/2015] [Indexed: 12/21/2022]
Abstract
Neonatal exposure to 17alpha-ethynylestradiol (EE) causes delayed effect, a late-occurring irreversible damage to reproductive functions characterized by the early onset of age-matched abnormal estrous cycling. To clarify the involvement of a hypothalamic key cycling regulator KiSS1/GPR54 in the delayed effect, we investigated artificially induced LH surges and KiSS1 mRNA expression in the anteroventral periventricular nucleus (AVPV) of cycling young adult rats neonatally exposed to EE, and compared these parameters to those in about 5 months old middle-aged rats. KiSS1 mRNA expression, the number of KiSS1-positive cells and KiSS1/ERα co-expressing cells in the AVPV decreased in both EE-exposed and middle-aged rats. The peak area and levels of LH surge dose-dependently decreased in EE-exposed rats, and reduction was more evident in middle-aged rats. These results indicate that the prior attenuation of KiSS1 and consequent depression of LH surges plays a key role in the onset of abnormal estrous cycling in the delayed effect.
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