Verification of responses of Japanese medaka (Oryzias latipes) to anti-androgens, vinclozolin and flutamide, in short-term assays.
Various testing methods for the detection of the endocrine disruptive activities of chemicals have been developed in freshwater fish species. However, a few relatively easier specific methods for detecting anti-androgenic activities are available for fish. The aim of this study was to verify the papillary process in Japanese medaka (Oryzias latipes) as an indicator of the anti-androgenic activity of chemicals. Japanese medaka were exposed to two types of anti-androgenic compounds, vinclozolin and flutamide, using two short-term assays; one was conformed to the existing short-term reproduction assay using adult fish (adult test) and the other was a test based on the same methods but using juvenile fish at the beginning of exposure (juvenile test). Significant decreases in male papillary processes were observed in the juvenile test treated with the highest concentration of both antiandrogens (640 µg l(-1) vinclozolin and 1000 µg l(-1) flutamide); however, no significant effects were observed in the adult test. Consequently, our results indicate that papillary processes in Japanese medaka can be used as the end-point for screening the anti-androgenic activity of chemicals using juvenile fish for a specific period based on the existing short-term reproduction assay.
Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan; Center for Environmental Risk Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan.
Ataru
A
Nakamura
Hitomi
H
Takanobu
Ikumi
I
Tamura
Masumi
M
Yamamuro
Taisen
T
Iguchi
Norihisa
N
Tatarazako
D000726:Androgen Antagonists / Q000633:toxicity*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D052244:Endocrine Disruptors / Q000633:toxicity*; D005260:Female; D005298:Fertility / Q000187:drug effects; D005485:Flutamide / Q000633:toxicity*; D006066:Gonads / Q000187:drug effects* / Q000254:growth & development; D008099:Liver / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D008297:Male; D009990:Oryzias / Q000254:growth & development*; D010080:Oxazoles / Q000633:toxicity*; D015203:Reproducibility of Results; D012727:Sex Characteristics; D013997:Time Factors; D018675:Toxicity Tests / Q000379:methods / Q000592:standards; D014819:Vitellogenins / Q000378:metabolism
D000726:Androgen Antagonists; D052244:Endocrine Disruptors; D010080:Oxazoles; D014819:Vitellogenins; D005485:Flutamide; C025643:vinclozolin
Japanese medaka; anti-androgen; endocrine disruption; flutamide; papillary processes; vinclozolin