Abstract: OBJECTIVE: To explore the effect of perinatal exposure to bisophenol A(BPA) on reproduction and development of the female offspring of SD rats and the changes of uterine estrogen receptor(ER) expression. METHODS: Pregnant Sprague-Dawley rats received by gavage 0, 5, 50 or 500 mg/(kg•d) of BPA from gestation day (PND) 6 to postnatal day (PND) 21. Uterus and ovarians were weighed and prepared for histological evaluation. The expression of ERα, ERβ, phosphorylated ERK (p-ERK) and total ERK (T-ERK) in uterus were measured. The change of uterine sensitivity to estradiol (E2) was investigated by the modified uterotrophic assay. RESULTS: The toxic symptoms in parental rats and decrease in body weight in female offsprings were observed in 500 mg/(kg•BW) group, but there was an increase in body weight and uterine weight in the 50 mg/(kg•BW) group. No pathological changes were found in BPA- treated group, the thickness of endometrial layer and the ratio to uterus was increased in all dosage groups compared with the control. The protein expressions of ERα and p-ERK but not ERβ in uterus were elevated in all dosage groups. The uterine sensitivity to E2 was increased in all BPA-treated groups. CONCLUSION: Perinatal exposure to Bisphenol A could induce the changes of ER expression in the uterus of female offspring rats and change the uterine physical structure by probably activating the ERK pathway.

Key words: Bisphenol A, female offspring, reproductive and developmental effects, estrogen receptor, extracellular regulated kinase