Pubertal exposure to bisphenol A affects the reproduction of male mice and sex ratio of offspring

Objective To study the effects of pubertal exposure to bisphenol A (BPA) on the reproduction of male mice in adulthood and subsequent generation mice. Methods Male mice aged 21 d were exposed to BPA at a dose of 50 mg/kg per day for 7 d by intraperitoneal injection. Sperm count, sperm deformity rate and testis histology were evaluated 35 d after exposure. Male fertility index and newborns were further observed by mating with the normal female mice. Results The epididymal sperm number was decreased by 20.6% in BPA exposure group compared with the control (P<0.01). Sperm deformity rate in BPA group was increased by 9.65% compared with the control (P<0.05). Testis seminiferous tubules were abnormal with sloughing of germ cells; BPA exposure had no significant effects on the fertility of male mice in adulthood; sex ratio of male to female offspring was increased. Conclusion Pubertal exposure to BPA disrupted spermatogenesis in adult mice, and the proportion of male offspring was increased compared with the control.