title: 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.
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.
authors.affiliation: Division of Pathology, National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan. Electronic address: midoriy@nihs.go.jp.
authors.forename: Midori
authors.initials: M
authors.lastname: Yoshida
authors.affiliation: Veterinary Physiology, Tokyo University of Agriculture and Technology, 3-5-8, Saiwaicho, Fuchu-shi, 183-8509 Tokyo, Japan.
authors.forename: Sayumi
authors.initials: S
authors.lastname: Katashima
authors.affiliation: Division of Pathology, National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
authors.forename: Miwa
authors.initials: M
authors.lastname: Tahahashi
authors.affiliation: 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.
authors.forename: Ryohei
authors.initials: R
authors.lastname: Ichimura
authors.affiliation: Division of Pathology, National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Inoue
authors.affiliation: Veterinary Physiology, Tokyo University of Agriculture and Technology, 3-5-8, Saiwaicho, Fuchu-shi, 183-8509 Tokyo, Japan.
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Taya
authors.affiliation: Veterinary Physiology, Tokyo University of Agriculture and Technology, 3-5-8, Saiwaicho, Fuchu-shi, 183-8509 Tokyo, Japan.
authors.forename: Gen
authors.initials: G
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D004968:Estrogens, Non-Steroidal / Q000633:toxicity*; D030762:Estrous Cycle / Q000187:drug effects; D005260:Female; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects*; D008297:Male; D010053:Ovary / Q000187:drug effects; D010636:Phenols / Q000633:toxicity*; D010913:Pituitary-Adrenal System / Q000187:drug effects*; D011247:Pregnancy; D051381:Rats; D012098:Reproduction / Q000187:drug effects*
chemical_list: D004968:Estrogens, Non-Steroidal; D010636:Phenols; C105260:4-tert-octylphenol
keywords: Delayed effect; Estrous cycle; Hypothalamic–pituitary axis; Ovary exchange; Postnatal exposure; p-tert-Octylphenol