Testicular Toxicity of Arsenic on Spermatogenesis in Fish

Arsenic (As), a well-known water pollutant, has been associated with various human health problems, however, studies pertaining to its reproductive toxicity on fish are very limited. In this study, we investigated the direct influence of As on fish spermatogenesis using Japanese eel (Anguilla japonica) in vitro testicular organ culture system. Eel testicular fragments were cultured in vitro with increasing concentrations of As with or without human chorionic gonadotropin (hCG). Thereafter, steroid synthesis, steroidogenic enzyme activity, testicular morphology and proliferation of germ cells were analyzed. As inhibits hCG-induced germ cell proliferation in a dose-dependent manner. Highest dose of As (100 μM) with hCG strongly induced germ cell apoptosis. Moreover, a dose of As (0.1 μM) lower than the WHO drinking water quality guideline most effectively suppressed 11-ketotestosterone (11KT) synthesis. At the same As concentration, 3.-hydroxysteroid dehydrogenase (3β-HSD) expression and activity were inhibited. A high oxidative DNA damage was observed in testicular fragments exposed to the same treatment (100 μM As + hCG) which caused apoptosis. These results suggest that low dose of As inhibits spermatogenesis via suppression of steroidogenic enzyme activity and expression while high dose of this compound induces oxidative stress-mediated germ cell apoptosis.