Induction of oxidative stress in the rat testis after short-term exposure to the organochlorine pesticide methoxychlor

Abstract.

Methoxychlor is one of the environmental contaminants that has been shown to induce reproductive abnormalities in male rats. The mechanism of action of methoxychlor on the male reproductive system remains unclear. In the present study we have sought to investigate whether short-term administration of methoxychlor induces oxidative stress in the testis of adult rats. Methoxychlor (50, 100, or 200 mg/kg body weight per day) was administered orally for 1, 4, or 7 days. The animals were killed using anesthetic ether on the day following the last dosing. The weights of epididymides, seminal vesicles, and ventral prostate decreased after 50, 100, or 200 mg/kg per day for 7 days but remained unchanged after 1 and 4 days of treatment. The production of superoxide anion and hydrogen peroxide increased in the animals that received methoxychlor for 4 and 7 days. The activities of the antioxidant enzymes superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase decreased, while the level of lipid peroxidation increased in the testis after 4 or 7 days of treatment. The results indicated that short-term exposure to methoxychlor induces oxidative stress in the testis by decreasing antioxidant enzymes and increasing lipid peroxidation, possibly by inducing reactive oxygen species. In conclusion, the adverse effect of methoxychlor on the male reproduction could be due to induction of oxidative stress in testis.