This Article Full Text Full Text (PDF) All Versions of this Article: 138/2/279    most recent REP-09-0167v1 Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Celino, F. T Articles by Miura, T. Search for Related Content PubMed PubMed Citation Articles by Celino, F. T Articles by Miura, T.

Arsenic inhibits in vitro spermatogenesis and induces germ cell apoptosis in Japanese eel (Anguilla japonica)

Research Group for Reproductive Physiology, South Ehime Fisheries Research Center, Ehime University, 1289-1 Funakoshi, Ainan 798-4292, Japan

Correspondence should be addressed to T Miura; Email: miutake{at}agr.ehime-u.ac.jp

The precise mechanism and direct effects of arsenic on fish, particularly in reproduction, are not well clarified. The aim of this study is to investigate the direct influence of arsenic on fish spermatogenesis using the Japanese eel (Anguilla japonica) in vitro testicular organ culture system. Eel testicular fragments were cultured in vitro with 0.1–100 µM arsenic with or without human chorionic gonadotropin (hCG) for 6 or 15 days at 20 °C. Arsenic treatment provoked a dose-dependent inhibition of hCG-induced germ cell proliferation as revealed by 5-bromo-2-deoxyuridine immunohistochemistry. Time-resolved fluorescent immunoassay showed that arsenic suppressed hCG-induced synthesis of 11-ketotestosterone (11-KT) in testicular fragments incubated with 0.0001–100 µM arsenic and hCG for 18 h. A 0.1 µM (7 µg/l) dose of arsenic which is lower than the World Health Organization drinking water quality guideline of 10 µg/l most effectively reduced 11-KT production. The hCG-induced synthesis of progesterone from pregnenolone was significantly inhibited by low doses of arsenic (0.1–1 µM), implying an inhibition of 3β-hydroxysteroid dehydrogenase activity. In situ TUNEL assays indicated that germ cells undergo apoptosis at the highest dose of arsenic (100 µM). An arsenic concentration-dependent increase in oxidative DNA damage was detected by 8-hydroxy-2'-deoxyguanosine (8-OHdG) immunohistochemistry. A peak in 8-OHdG index was observed in testicular fragments treated with 100 µM arsenic and hCG consistent with the TUNEL results. These data suggest that low doses of arsenic may inhibit spermatogenesis via steroidogenesis suppression, while high doses of arsenic induce oxidative stress-mediated germ cell apoptosis.