Organotin compounds have been widely used as antifouling paints for ships. However, once these compounds are released into the aquatic environment, they act as environmental hazards. One of the well-known effects of organotin compounds is the endocrine-disrupting activity on marine snails. Tributyltin chloride (TBTC) has been shown to induce imposex in female gastropods, producing male genitals to female ones. However, the effects of organotin compounds on the reproduction of mammal are largely unknown. Here we demonstrate the toxicity of TBTC on mammalian reproduction. Histopatholotical examination of testes of rats treated with TBTC showed the loss of interstitial tissue. Histochemical staining showed the accumulation of organotin in the interstitial tissue. As there are leydig cells responsible for the production of androgens in the interstitial tissue, we examined the concentration of testosterone in the blood. The concentration of testosterone was decreased significantly by the TBTC administration. These results indicate that TBTC can act as toxicant to the mammalian reproduction system by damaging the leydig cells in the interstitial tissue and by which disturbing the production of testosterone.
