title: Effect of 17beta-estradiol on the reproduction of Japanese medaka (Oryzias latipes).
abstract: Estrogenic compounds such as 17beta-estradiol (E2) and its analogs are present in the aquatic environment and can adversely affect the reproductive systems of aquatic organisms. Although E2 has been detected at a maximum concentration of 64 ng/l in effluents of sewage treatment works (STWs), few reports address the associated effects on reproduction in fish. Therefore, we exposed adult medaka (Oryzias latipes) to mean measured E2 concentrations of 29.3, 55.7, 116, 227, and 463 ng/l for 21 d and assessed the effects on the egg number and fertility of paired medaka during the exposure period. In addition, we determined the hepatic vitellogenin (Vtg) concentration and histologically assessed the gonads of these fish. The number of egg produced and fertility of the paired medaka exposed to 463 ng/l E2 were significantly less compared with those of the control fish. Males in all treatment groups had developed testis-ova. Males treated with E2 concentrations = 55.7 ng/l contained relating great concentrations of hepatic Vtg. Therefore, although only the greatest E2 concentration tested in our study affected fecundity and fertility, effects of E2 were observed on induction of Vtg and testis-ova in male medaka exposed to environmentally relevant concentrations of E2.
authors: Department of Bioscience and Biotechnology, Kyushu University Graduate School, Fukuoka, Japan.
authors: Ik Joon
authors: IJ
authors: Kang
authors: Hirofumi
authors: H
authors: Yokota
authors: Yuji
authors: Y
authors: Oshima
authors: Yukinari
authors: Y
authors: Tsuruda
authors: Tomomi
authors: T
authors: Yamaguchi
authors: Masanobu
authors: M
authors: Maeda
authors: Nobuyoshi
authors: N
authors: Imada
authors: Hiroshi
authors: H
authors: Tadokoro
authors: Tsuneo
authors: T
authors: Honjo
mesh_terms: D000818:Animals; D004781:Environmental Exposure; D004958:Estradiol / Q000009:adverse effects*; D005260:Female; D005298:Fertility / Q000187:drug effects*; D008297:Male; D009990:Oryzias / Q000502:physiology*; D010053:Ovary / Q000002:abnormalities / Q000187:drug effects; D013737:Testis / Q000002:abnormalities / Q000187:drug effects; D014873:Water Pollutants / Q000009:adverse effects*
chemical_list: D014873:Water Pollutants; D004958:Estradiol