Light and Transmission Electron Microscopic Studies on Subacute Toxicity of Bisphenol A on the Rat Ovary.

To investigate subacute toxicity of Bisphenol A (BPA) in adult rat ovaries using gastric intubation daily for 4 weeks by light and transmission electron microscopy.Fifteen rats were included in the study and divided into 2 groups: 12 rats were used for BPA administration (600 mg/kg body weight), and 3 rats received only vehicle and served as controls. The ovaries of both treated and control rats were taken at 1, 2, 3, and 4 weeks postadministration, fixed in 10% neutral buffered formalin, and processed for light microscopy. Ovarian samples at the 4th week postexposure were fixed in 3% glutaraldehyde and processed for transmission electron microscopy.The main histopathological alterations were observed at the 3rd and 4th weeks postexposure. Atretic follicles,formation of cysts, separation of granulosa cells, and hyperemia of blood vessels were observed. Moreover, a marked increase in the thickness of the tunica albuginea was determined (33.8 ± 1.72 μm and 34.8 ± 1.72 μm, respectively,for the 3rd and 4th weeks as compared to the control group (13.78 ± 0.12 μm). Transmission electron microscopy showed marked lipid droplet accumulation, chromatin condensation in the nuclei of granulosa cells, and presence of autophagosomes in the treated group at 4 weeks postexposure as compared to the nonexposed group (control group).The results of the present study suggest altered or disrupted ovulation. Moreover, change in the thickness of the tunica albuginea observed during the course of exposure may play a role in such disrupted ovulation.