EVALUATION OF THE PROTECTIVE ROLE OF MELATONIN AGAINST ORGANIC MERCURY-INDUCED DEVELOPMENTAL TOXICITY IN MICE

The embryotoxic and teratogenic effects of methylmercury in mammals ar e well known. In the present study, we assessed whether melatonin (MLT ), a pineal hormone with a well established antioxidant activity, coul d act as a defense against methylmercury chloride (MMC)-induced matern al and developmental toxicity in mice. On gestational days 10-13, a se ries of 4 doses of MLT were given by gavage to pregnant mice following a single oral exposure to 25 mg/kg of MMC on day 10 of gestation. MLT was administered at 0, 40, and 100 mg/kg/day. Three additional groups of MMC-untreated pregnant mice received the same MLT doses on the sam e gestational days. Although some beneficial effects of MLT on MMC-ind uced maternal and fetal toxicity could be observed, those effects did not reach the level of statistical significance, Consequently, under t he current experimental conditions MLT would not be an effective agent in protecting against MMC-induced developmental toxicity.