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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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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: 3] [Impact Index Per Article: 0.4] [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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3
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Abstract
Silent Spring by Rachel Carson (1962) established a role for environmental chemicals in cancer and Our Stolen Future by Theo Colbone, Dianne Dumanoski and John Peterson Myers (1996) coined the concept of "Endocrine Disrupting Chemicals (EDCs)" with its mechanistic plausibility for all the living organisms. For basic biologists, seeing a non-monotonic dose-response curve was a matter of course. In contrast, for the toxicologists at that time, the dose-response curves should be monotonic. It took some time for toxicologists to accept the plausibility that animals and humans are subject to the effects of EDCs act in a way that is explained by the new paradigm of receptor-mediated toxicity or in other words "signal toxicity." In classical toxicology, a toxic substance reaches a cellular target and induces malfunction. The target molecules are proteins including enzymes, lipid membranes, DNA, and other components of the cell which are damaged by the toxic substances. On the other hand, in the case of signal toxicity, a chemical binds to a specific receptor - after that, the chemical itself is not important. The signal from the receptor initiates a cascade of molecular events that leads to various changes in the cells and organs. When the signal is abnormal for a cell or an organ in terms of quality, intensity and timing, then the signal will induce adverse effects to the target. An extreme example of signal toxicity is the 1981 Nobel Prize in Physiology or Medicine work by Drs. Hubel and Wiesel. They blocked the signal of sharp images from the retina to the brain and found that the visual cortex needed this signal at the correct time for its proper development. In humans, such signal disruption is well known to induce "form-deprivation amblyopia" in infants. The concept of signal toxicity widens the range of systems vulnerable to EDCs and facilitates the understanding of their biological characteristics. For example, compared with intrinsic ligands, xenobiotic chemicals usually act as weak agonists and/or weak antagonists of receptor systems; the dose-response characteristics and the dose range will depend on the signaling system of concern. If the signal is used for organogenesis and functional maturation, there would be a critical period in the development during which the disturbance of such signals may cause irreversible changes. Since recepter-based signaling mechanisms are usually an amplification systems, it is hard to set a threshold in its dose response, and the outcome of signal toxicity is often stochastic at low doses. This review attempts to explain the benefits of incorporating the concept of signal toxicology for widening the range of toxicology for the better protection of human and environmental health in modern civilized life, where chemicals are designed to be less toxic in terms of traditional toxicity but not yet in "signal toxicity."
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Affiliation(s)
- Jun Kanno
- Japan Bioassay Research Center, Japan Organization of Occupational Health and Safety
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Ohmukai H, Negura T, Tachibana S, Ohta R. Genetic variation in low-dose effects of neonatal DES exposure in female rats. Reprod Toxicol 2017; 73:322-327. [PMID: 28734970 DOI: 10.1016/j.reprotox.2017.07.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 03/26/2017] [Accepted: 07/12/2017] [Indexed: 11/25/2022]
Abstract
To confirm genetic variation in low-dose effects of diethylstilbestrol (DES), two inbred strains of rats, which have been selectively bred for high- and low-avoidance learning (HAA and LAA, respectively), were used in this study. LAA rats characteristically show later sexual maturation, earlier reproductive senescence, and lower body weight as compared to HAA rats. Female neonates of each strain were daily administered DES by oral gavage at doses of 0 (vehicle only), 0.05 and 0.5μg/kg for the first 5days after birth. As a result, early onset of abnormal estrous cycles was observed during the same period in HAA and LAA rats treated with 0.5μg/kg. However, accelerated puberty and excessive body weight gains were observed only in LAA rats treated with 0.05 and 0.5μg/kg. These results suggest that the effects of neonatal DES exposure vary with the genetic background of the female rats used.
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Affiliation(s)
- Hideo Ohmukai
- Hatano Research Institute, Food and Drug Safety Center, 729-5 Ochiai, Hadano Kanagawa, 257-8523, Japan
| | - Tsukasa Negura
- Hatano Research Institute, Food and Drug Safety Center, 729-5 Ochiai, Hadano Kanagawa, 257-8523, Japan
| | - Shigehiro Tachibana
- Hatano Research Institute, Food and Drug Safety Center, 729-5 Ochiai, Hadano Kanagawa, 257-8523, Japan
| | - Ryo Ohta
- Hatano Research Institute, Food and Drug Safety Center, 729-5 Ochiai, Hadano Kanagawa, 257-8523, Japan.
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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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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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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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Delayed adverse effects of neonatal exposure to polymeric nanoparticle poly(ethylene glycol)-block-polylactide methyl ether on hypothalamic–pituitary–ovarian axis development and function in Wistar rats. Reprod Toxicol 2015; 57:165-75. [DOI: 10.1016/j.reprotox.2015.07.072] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 07/08/2015] [Accepted: 07/09/2015] [Indexed: 01/23/2023]
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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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10
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Yoshida M, Katashima S, Tahahashi M, Ichimura R, Inoue K, Taya K, Watanabe G. Predominant role of the hypothalamic-pituitary axis, not the ovary, in different types of abnormal cycle induction by postnatal exposure to high dose p-tert-octylphenol in rats. Reprod Toxicol 2015; 57:21-8. [PMID: 25975844 DOI: 10.1016/j.reprotox.2015.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 03/31/2015] [Accepted: 05/01/2015] [Indexed: 10/23/2022]
Abstract
To determine whether it is the hypothalamic-pituitary axis or the ovary that plays the predominant role in abnormal estrous cycling induction by postnatal exposure to estrogenic compounds, female rats were subcutaneously injected with 100mg/kg p-tert-octylphenol or vehicle for 5 or 15 days after birth (OP-PND5, OP-PND15 or control). Ovaries were exchanged between control and treated groups on PND28. Controls receiving control or OP-PND5 ovaries showed normal cycles within 4 weeks after the exchange, and corpora lutea were detected in transplanted ovaries. Controls receiving OP-PND15 ovaries consistently increased persistent estrus (PE). OP-PND15 rats receiving control or OP-PND15 ovaries immediately descended into PE, and transplanted ovaries were atrophic with cystic follicles, indicating anovulation. OP-PND5 rats receiving control or OP-PND5 ovaries showed early onset of PE after normal cycling. The hypothalamic-pituitary axis is predominant in abnormal cycling induction by postnatal exposure to OP. OP-PND15 ovaries were impaired compared to other groups.
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Affiliation(s)
- Midori Yoshida
- Division of Pathology, National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
| | - Sayumi Katashima
- Veterinary Physiology, Tokyo University of Agriculture and Technology, 3-5-8, Saiwaicho, Fuchu-shi, 183-8509 Tokyo, Japan
| | - Miwa Tahahashi
- 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; Veterinary Physiology, Tokyo University of Agriculture and Technology, 3-5-8, Saiwaicho, Fuchu-shi, 183-8509 Tokyo, Japan
| | - Kaoru Inoue
- Division of Pathology, National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan
| | - Kazuyoshi Taya
- Veterinary Physiology, Tokyo University of Agriculture and Technology, 3-5-8, Saiwaicho, Fuchu-shi, 183-8509 Tokyo, Japan
| | - Gen Watanabe
- Veterinary Physiology, Tokyo University of Agriculture and Technology, 3-5-8, Saiwaicho, Fuchu-shi, 183-8509 Tokyo, Japan
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11
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Takahashi M, Inoue K, Morikawa T, Matsuo S, Hayashi S, Tamura K, Watanabe G, Taya K, Yoshida M. Early indicators of delayed adverse effects in female reproductive organs in rats receiving neonatal exposure to 17alpha-ethynylestradiol. J Toxicol Sci 2015; 39:775-84. [PMID: 25242408 DOI: 10.2131/jts.39.775] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We previously reported that neonatal exposure to 17α-ethynylestradiol (EE) led to delayed adverse effects in which age-related anovulation after sexual maturation was accelerated. To identify early indicators of these adverse effects, female Wistar Hannover GALAS rats received a single EE injection (0, 0.02, 0.2, 2, 20, or 200 μg/kg) within 24 hr of birth. Histopathological changes in ovarian and uterine development were investigated from postnatal day (PND) 14 to 10 weeks of age. Immunohistochemical expression of estrogen receptor alpha (ERα) in the uterus, serum levels of sex-related hormones and gene expression in the hypothalamus were examined. Although neonatal exposure to EE did not affect body growth or ovarian development, serum FSH tended to decrease at doses ≥ 2 μg/kg, and Kiss1 mRNA level in the whole hypothalamus was significantly decreased in all EE-treated groups at PND14.The number of uterine glands at PND21 was suppressed at doses ≥ 20 μg/kg, and ERα expression in the uterine epithelium at estrus stage decreased in a dose-dependent manner at 10 weeks of age. These results demonstrated that the various identified changes that occurred before the appearance of delayed adverse effects could be candidate early indicators.
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Affiliation(s)
- Miwa Takahashi
- Division of Pathology, National Institute of Health Sciences
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12
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Bhandari RK, Deem SL, Holliday DK, Jandegian CM, Kassotis CD, Nagel SC, Tillitt DE, Vom Saal FS, Rosenfeld CS. Effects of the environmental estrogenic contaminants bisphenol A and 17α-ethinyl estradiol on sexual development and adult behaviors in aquatic wildlife species. Gen Comp Endocrinol 2015; 214:195-219. [PMID: 25277515 DOI: 10.1016/j.ygcen.2014.09.014] [Citation(s) in RCA: 180] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Revised: 08/08/2014] [Accepted: 09/20/2014] [Indexed: 12/12/2022]
Abstract
Endocrine disrupting chemicals (EDCs), including the mass-produced component of plastics, bisphenol A (BPA) are widely prevalent in aquatic and terrestrial habitats. Many aquatic species, such as fish, amphibians, aquatic reptiles and mammals, are exposed daily to high concentrations of BPA and ethinyl estradiol (EE2), estrogen in birth control pills. In this review, we will predominantly focus on BPA and EE2, well-described estrogenic EDCs. First, the evidence that BPA and EE2 are detectable in almost all bodies of water will be discussed. We will consider how BPA affects sexual and neural development in these species, as these effects have been the best characterized across taxa. For instance, such chemicals have been in many cases reported to cause sex-reversal of males to females. Even if these chemicals do not overtly alter the gonadal sex, there are indications that several EDCs might demasculinize male-specific behaviors that are essential for attracting a mate. In so doing, these chemicals may reduce the likelihood that these males reproduce. If exposed males do reproduce, the concern is that they will then be passing on compromised genetic fitness to their offspring and transmitting potential transgenerational effects through their sperm epigenome. We will thus consider how diverse epigenetic changes might be a unifying mechanism of how BPA and EE2 disrupt several processes across species. Such changes might also serve as universal species diagnostic biomarkers of BPA and other EDCs exposure. Lastly, the evidence that estrogenic EDCs-induced effects in aquatic species might translate to humans will be considered.
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Affiliation(s)
- Ramji K Bhandari
- Biological Sciences, University of Missouri, Columbia, MO 65211, USA; Columbia Environmental Research Center, U.S. Geological Survey, Columbia, MO 65201, USA
| | - Sharon L Deem
- Institute for Conservation Medicine, Saint Louis Zoo, Saint Louis, MO 63110, USA; Veterinary Clinical Medicine, University of Missouri, Columbia, MO 65211, USA
| | - Dawn K Holliday
- Department of Biology and Environmental Science, Westminster College, Fulton, MO 65251, USA; Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, MO 65211, USA
| | - Caitlin M Jandegian
- Columbia Environmental Research Center, U.S. Geological Survey, Columbia, MO 65201, USA; Institute for Conservation Medicine, Saint Louis Zoo, Saint Louis, MO 63110, USA; Masters in Public Health Program, University of Missouri, Columbia, MO 65211, USA
| | | | - Susan C Nagel
- Biological Sciences, University of Missouri, Columbia, MO 65211, USA; Obstetrics, Gynecology, & Women's Health, University of Missouri, Columbia, MO 65211, USA
| | - Donald E Tillitt
- Columbia Environmental Research Center, U.S. Geological Survey, Columbia, MO 65201, USA
| | | | - Cheryl S Rosenfeld
- Biomedical Sciences, University of Missouri, Columbia, MO 65211, USA; Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA; Genetics Area Program Faculty Member, University of Missouri, Columbia, MO 65211, USA.
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13
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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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14
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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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15
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Ohta R, Ohmukai H, Toyoizumi T, Shindo T, Marumo H, Ono H. Ovarian dysfunction, obesity and pituitary tumors in female mice following neonatal exposure to low-dose diethylstilbestrol. Reprod Toxicol 2014; 50:145-51. [PMID: 25450423 DOI: 10.1016/j.reprotox.2014.10.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 10/23/2014] [Accepted: 10/24/2014] [Indexed: 11/28/2022]
Abstract
In a previous study, we found that early life exposure to low-dose diethylstilbestrol (DES) induced early onset of spontaneous abnormalities in estrus cycle and shortened survival in female Sprague-Dawley rats. In order to confirm the repeatability of the previous study, neonates of C57BL/6J mice were orally administered DES at doses of 0.005, 0.05, 0.5 and 5 μg/kg/day, and the aging of their reproductive function was observed. As a result, delayed toxicity on ovarian function was found in females treated with 0.5 μg/kg/day of DES. Concomitantly, the females in the 0.05 μg/kg/day of DES, or greater, groups, had increased body weights and, in the 0.5 μg/kg/day of DES, or greater, groups, had developed pituitary tumors, which were causal factors in their accelerated mortality. Thus, we found that early life exposure to low-dose DES induced early onset of spontaneous abnormalities in estrus cycle not only in female rats but also in female mice.
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Affiliation(s)
- Ryo Ohta
- Hatano Research Institute, Food and Drug Safety Center, 729-5 Ochiai, Hadano, Kanagawa 257-8523, Japan.
| | - Hideo Ohmukai
- Hatano Research Institute, Food and Drug Safety Center, 729-5 Ochiai, Hadano, Kanagawa 257-8523, Japan
| | - Tomoyasu Toyoizumi
- Hatano Research Institute, Food and Drug Safety Center, 729-5 Ochiai, Hadano, Kanagawa 257-8523, Japan
| | - Tomoko Shindo
- Hatano Research Institute, Food and Drug Safety Center, 729-5 Ochiai, Hadano, Kanagawa 257-8523, Japan
| | - Hideki Marumo
- Hatano Research Institute, Food and Drug Safety Center, 729-5 Ochiai, Hadano, Kanagawa 257-8523, Japan
| | - Hiroshi Ono
- Hatano Research Institute, Food and Drug Safety Center, 729-5 Ochiai, Hadano, Kanagawa 257-8523, Japan
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16
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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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17
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Nozawa K, Nagaoka K, Zhang H, Usuda K, Okazaki S, Taya K, Yoshida M, Watanabe G. Neonatal exposure to 17α-ethynyl estradiol affects ovarian gene expression and disrupts reproductive cycles in female rats. Reprod Toxicol 2014; 46:77-84. [PMID: 24632129 DOI: 10.1016/j.reprotox.2014.03.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 02/27/2014] [Accepted: 03/03/2014] [Indexed: 01/10/2023]
Abstract
Neonatal exposure to synthetic estrogen causes delayed reproductive dysfunction in female rats. Exposure to 17α-ethynyl estradiol (EE, low: 20 and high: 2000 μg/kg) induced an abnormal estrous cycle during PND171-190 in low-dose and PND126-145 in high-dose group. At PND90 within normal estrous cycle, high-dose animals showed lack of LH surge and low of ovarian hormones in serum level. Gene expression analysis demonstrated that level of mRNA encoding luteinizing hormone/chorionic gonadotropin receptor (LHCGR) was higher in EE-treated ovaries than in control ovaries, and LHCGR protein colocalized with apoptosis-related proteins in the interstitial area of the ovary. At PND1, ovarian LHCGR mRNA levels were higher in EE-treated rats than in control rats, and direct induction of LHCGR expression by EE was observed in vitro. Our results indicate that neonatal exposure to EE induces irregular LHCGR expression in the immature ovary, which may influence the occurrence of delayed reproductive dysfunction in adult animals.
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Affiliation(s)
- Kaori Nozawa
- Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
| | - Kentaro Nagaoka
- Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan.
| | - Haolin Zhang
- Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
| | - Kento Usuda
- Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
| | - Sachiko Okazaki
- Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
| | - Kazuyoshi Taya
- Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
| | - Midori Yoshida
- 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, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
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18
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Delclos KB, Camacho L, Lewis SM, Vanlandingham MM, Latendresse JR, Olson GR, Davis KJ, Patton RE, Gamboa da Costa G, Woodling KA, Bryant MS, Chidambaram M, Trbojevich R, Juliar BE, Felton RP, Thorn BT. Toxicity evaluation of bisphenol A administered by gavage to Sprague Dawley rats from gestation day 6 through postnatal day 90. Toxicol Sci 2014; 139:174-97. [PMID: 24496637 DOI: 10.1093/toxsci/kfu022] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Bisphenol A (BPA) is a high production volume industrial chemical to which there is widespread human oral exposure. Guideline studies used to set regulatory limits detected adverse effects only at doses well above human exposures and established a no-observed-adverse-effect level (NOAEL) of 5 mg/kg body weight (bw)/day. However, many reported animal studies link BPA to potentially adverse effects on multiple organ systems at doses below the NOAEL. The primary goals of the subchronic study reported here were to identify adverse effects induced by orally (gavage) administered BPA below the NOAEL, to characterize the dose response for such effects and to determine doses for a subsequent chronic study. Sprague Dawley rat dams were dosed daily from gestation day 6 until the start of labor, and their pups were directly dosed from day 1 after birth to termination. The primary focus was on seven equally spaced BPA doses (2.5-2700 μg/kg bw/day). Also included were a naïve control, two doses of ethinyl estradiol (EE2) to demonstrate the estrogen responsiveness of the animal model, and two high BPA doses (100,000 and 300,000 μg/kg bw/day) expected from guideline studies to produce adverse effects. Clear adverse effects of BPA, including depressed gestational and postnatal body weight gain, effects on the ovary (increased cystic follicles, depleted corpora lutea, and antral follicles), and serum hormones (increased serum estradiol and prolactin and decreased progesterone), were observed only at the two high doses of BPA. BPA-induced effects partially overlapped those induced by EE2, consistent with the known weak estrogenic activity of BPA.
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Affiliation(s)
- K Barry Delclos
- Division of Biochemical Toxicology, 3900 NCTR Road, Jefferson, Arkansas 72079
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19
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Takahashi M, Inoue K, Morikawa T, Matsuo S, Hayashi S, Tamura K, Watanabe G, Taya K, Yoshida M. Delayed effects of neonatal exposure to 17alpha-ethynylestradiol on the estrous cycle and uterine carcinogenesis in Wistar Hannover GALAS rats. Reprod Toxicol 2013; 40:16-23. [PMID: 23707403 DOI: 10.1016/j.reprotox.2013.05.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 05/12/2013] [Accepted: 05/15/2013] [Indexed: 10/26/2022]
Abstract
We investigated the delayed effects of neonatal exposure to 17α-ethynylestradiol (EE) on the female reproductive tract using Wistar Hannover GALAS rats. Female pups received single injections of EE (0, 0.02, 0.2, 2, 20, or 200 μg/kg) within 24h after birth and estrous cyclicity was observed until 10 months of age. All animals were treated at 9 weeks of age with the uterine carcinogen, N-ethyl-N'-nitro-N-nitrosoguanidine. Although the vaginal opening was not affected, abnormal cycles were significantly increased from 0.2 μg/kg. Persistent estrus was prominent and the incidence increased age- and dose-dependently. Severity of atypical hyperplasia of the uterus tended to increase from 2 μg/kg. In these groups, serum progesterone level was lowered relative to estradiol level. In conclusion, estrous cyclicity was a sensitive indicator reflecting delayed effects on the female reproductive tract. Early onset of anovulation leading to prolonged estrogen exposure might be a risk factor for uterine carcinogenesis.
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Affiliation(s)
- Miwa Takahashi
- Division of Pathology, National Institute of Health Sciences, Setagaya-ku, Tokyo, Japan.
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20
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Shirota M, Kawashima J, Nakamura T, Ogawa Y, Kamiie J, Shirota K. Vascular hamartoma in the uterus of a female Sprague-Dawley rat with an episode of vaginal bleeding. Toxicol Pathol 2013; 41:1011-5. [PMID: 23416960 DOI: 10.1177/0192623313476575] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
An annular, reddened lesion with mild serosal hemorrhage and no tumorous mass formation was detected in the right uterine horn of a 37-week-old female Sprague-Dawley rat that had postpubertal vaginal bleeding. Histological examination revealed prominent proliferation of the endometrium, which occupied the uterine lumen. There were numerous aberrant vascular spaces filled with erythrocytes, proliferation of stromal cells, and inflammatory infiltrates including hemosiderin-laden macrophages in the endometrium. These vasculatures extended into the myometrium, and in a transverse section of the lesion, they were mostly distributed throughout the circumference of the uterus. They were irregular in shape and interconnected, forming a large vascular sinus and anastomosing reticular channels. In the area with serosal hemorrhage, the muscular layer covering the large irregular vascular space had undergone degeneration and necrosis. The lining cells of the vasculatures were often plump, and they protruded into the lumen and were arranged in a tombstone or hobnail manner. Immunostaining revealed that these cells were positive for von Willebrand factor and CD34. The aberrant vasculatures were not accompanied by pericytes or muscular layer, although a discontinuous muscular wall was present around some of them. From these results, the uterine lesion was diagnosed as a vascular hamartoma.
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Affiliation(s)
- Mariko Shirota
- 1Laboratory of Comparative Toxicology, Azabu University, Sagamihara, Japan
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