title: Anti-androgen flutamide affects gonadal development and reproduction in medaka (Oryzias latipes).
abstract: The effects of an anti-androgenic chemical on the reproduction of medaka (Oryzias latipes) were examined. Six mating pairs of medaka were exposed to flutamide (FLU) at measured concentrations of 0.101, 0.202, 0.397, 0.787, or 1.56 mg/L for 3 weeks. During the exposure period, one female died in the 1.56-mg/L treatment group, but no lesions or pathological abnormalities were observed. The fecundity and fertility of paired medaka were significantly decreased at 1.56 mg/L compared with those of the controls. Histological examination showed intersex gonads (testis-ova) in males exposed to FLU at 0.202, 0.397, and 0.787 mg/L. However, concentrations of hepatic vitellogenin (Vtg) in both sexes were not statistically different from those in the controls. These results demonstrate that FLU affected gonadal development in male medaka and reproductive capacity in paired medaka. This is the first report of testis-ova in male medaka exposed to FLU.
authors.affiliation: Division of Bioresource and Bioenvironmental Sciences, Kyushu University Graduate School, Hakozaki 6-10-1, Higashi-ku, Fukuoka 812-8581, Japan.
authors.forename: Ik Joon
authors.initials: IJ
authors.lastname: Kang
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hano
authors.forename: Yuji
authors.initials: Y
authors.lastname: Oshima
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Yokota
authors.forename: Yukinari
authors.initials: Y
authors.lastname: Tsuruda
authors.forename: Yohei
authors.initials: Y
authors.lastname: Shimasaki
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Honjo
mesh_terms: D000726:Androgen Antagonists / Q000633:toxicity*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D005485:Flutamide / Q000633:toxicity*; D006066:Gonads / Q000187:drug effects* / Q000254:growth & development; D008099:Liver / Q000737:chemistry; D008297:Male; D009990:Oryzias / Q000502:physiology*; D012098:Reproduction / Q000187:drug effects*; D014819:Vitellogenins / Q000032:analysis
chemical_list: D000726:Androgen Antagonists; D014819:Vitellogenins; D005485:Flutamide