Induction of oxidative stress by bisphenol A in the epididymal sperm of rats

Bisphenol A has been shown to affect the reproduction of male rats and mice. However, the mechanism of action of bisphenol A on the epididymal sperm is not elucidated. The present study was undertaken to evaluate the effect of bisphenol A on the antioxidant system of rat epididymal sperm. Bisphenol A was administered orally to male rats at the dose levels of 0.2, 2 and 20 mug/Kg body weight per day for 45 days. After 24 h of the last treatment, rats were weighed and killed using anesthetic ether. The body weight of treated rats did not show significant change as compared with the corresponding control groups. In bisphenol A-treated rats there was a significant decrease in the weight of the testis and epididymis; the weight of ventral prostate increased significantly whereas there was no significant change in the weight of seminal vesicles as compared with the corresponding group of control animals. Sperm collected from the epididymis were used for sperm count and biochemical estimations. Administration of bisphenol A caused a reduction in the epididymal sperm motility and sperm count in a dose-dependent manner. The activities of superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase were decreased while the levels of H2O2 and lipid peroxidation increased significantly in the treated rats as compared with the corresponding group of control animals. The results suggested that graded doses of bisphenol A elicit depletion of antioxidant defence system and induce oxidative stress in epididymal sperm of rats. In conclusion, the adverse effect of bisphenol A on male reproduction may be due to induction of oxidative stress in sperm. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.