Effects of Bisphenol A on Testosterone Levels and Sexual Behaviors of Male Mice

Objective: To evaluate the effects of bisphenol A (BPA) on testosterone levels and sexual behaviors of male mice. Methods: Forty 12-week-old male mice, 22 - 25 g, were randomly allocated into four equal groups (n = 10 per group): the control group and three BPA exposure groups including low concentration group (10 mg/kg), middle concentration group (50 mg/kg) and high concentration group (100 mg/kg). Each mouse received BPA intraperitoneally injected for 21 consecutive days. Sexual behaviors and testosterone levels in serum and interstitial tissue of testis were measured after the last administration of BPA. Furthermore, we also observed the weights of sexual organs of each group, including testis, epididymis and seminal vesicle. Results: The mount latency in the high concentration group, the intromission latency in the middle and the high concentration group were 11.64 ± 2.67 min, 20.28 ± 3.40 min and 20.13 ± 2.06 min respectively. All of them were longer than the control group (all P < 0.05). The mount frequency, intromission frequency and copulatory efficacy in the high concentration group were 0.52 ± 0.15 numbers/min, 0.37 ± 0.12 numbers/min and 0.40 ± 0.03, which were all statistically lower than the control group (all P < 0.05). The average testis weights in the low, middle and high concentration group were 0.198 ± 0.032 g, 0.203 ± 0.037g and 0.183 ± 0.032 g, and the relative testis weight in the high concentration group was 0.637 ± 0.106. All of these data were lower than the control group (P < 0.05, P < 0.05, P < 0.01 and P < 0.05, respectively). The epididymis weight and the relative epididymis weight, the weight of seminal vesicle and the relative weight of seminal vesicle were 0.069 ± 0.010 g, 0.242 ± 0.040, 0.219 ± 0.042 g and 0.760 ± 0.143, and all of them were lower than the control group (all P < 0.05). The serum testosterone levels in the high concentration group, the intratesticular testosterone levels in the middle and the high concentration group were 7.88 ± 1.62 ng/ml, 75.5 ± 7.18 ng/g and 73.00 ± 9.57 ng/g, which were all lower than the control group (all P < 0.05). Conclusions: BPA can decline the testosterone levels in mice and inhibit their sexual behaviors.