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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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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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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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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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Shirota M, Kawashima J, Nakamura T, Kamiie J, Shirota K, Yoshida M. Dose-dependent acceleration in the delayed effects of neonatal oral exposure to low-dose 17α-ethynylestradiol on reproductive functions in female Sprague-Dawley rats. J Toxicol Sci 2015; 40:727-38. [DOI: 10.2131/jts.40.727] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Mariko Shirota
- Laboratory of Comparative Toxicology, School of Veterinary Medicine
| | - Jun Kawashima
- Laboratory of Comparative Toxicology, School of Veterinary Medicine
| | | | | | - Kinji Shirota
- Laboratory of Veterinary Pathology, Azabu University
- Research Institute of Biosciences, Azabu University
| | - Midori Yoshida
- Division of Pathology, National Institute of Health Sciences
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