Uterine molecular responses to bisphenol A treatment before and after decidual induction in pseudopregnant rats

The results of the study demonstrate that the weak estrogenic action of bisphenol A (a daily subcutaneous dose of 200 mg/kg on 4 consecutive days, administered before or after decidual induction that occurs on day 4 of pseudopregnancy) on deciduoma growth in pseudopregnant Sprague-Dawley rats, was functionally associated with the hormonal status of the uterus. Whereas bisphenol A displayed uterotrophic action during the pre-decidual, estrogen related period, it inhibited decidual growth and progesterone secretion during the post-decidual, progesterone-dominated period. The estrogenic action of bisphenol A on uterine decidual growth was not correlated with the reduced levels of estrogen receptor binding sites and mRNA expression, nor the unchanged serum estradiol concentrations. BPA action appeared to be antagonized by progesterone.