Hormonal changes in male bisphenol-A treated spraguey dawley rats at different time response / Mazlieana Hidayah Abu Hassan Basri

The effects of Bisphenol-A (BPA) on hormonal changes in juvenile male Sprague­ Dawley (SD) rats at different time response (7, 14 and 28 days) of treatment was observed in this study from PND28-56. In this study nine groups were prepared for BPA, ethinyl estradiol (EE) and Tween-80 in distilled water (1:9 v/v) treatments on three different duration of time. Three groups of rats were administered orally with 100 mg/kg body weight of BPA. Another three groups of rats were administered orally with 100 mg/kg body weight of EE. Control group was administered with the vehicle of Tween- 80 with corn oil (1:9 v/v). The observations and analysis made in this study was the changes of the testosterone hormone levels for BPA, EE and control groups at 7, 14 and 28 days .. Statistical analysis by two-way ANOV A showed that treatments at different time response has significantly (p<0.05) influence the testosterone levels. Modifications in the circulating testosterone levels were observed after treatments. Testosterone was reduced in testosterone levels of the juveniles, both with BPA and EE compared to control groups. The level of testosterone concentration for BPA and EE groups were lower than negative control group while testosterone level for BPA group was lower than EE group. This can be due to the much higher estrogenic potency of EE; the potency of BPA is approximately 10 to 1000-fold less than that of EE. The testosterone levels were low for 7 days treatment (93.78 ± 14.51 pg/ml) and higher for 14 days treatment (159.91 ± 26.63 pg/ml) compared to 28 days treatment (149.84 ± 36.95 pg/ml). Statistical analysis by one-way ANOV A at p-value=0.05 shows there were no significance mean difference of testosterone levels between 7, 14 and 28 days treatment. Testosterone levels were significantly highest in negative control group (l 84.4638±35.79038 pg/ml), followed by positive control group (156.9857 ± 22.03493 pg/ml) and the lowest in BPA-treated group (62.0767±15.25640 pg/ml). There were significant differences of testosterone levels between BPA, EE and control groups.