Effect of mifepristone on steroid receptors and endocrine in human decidua of early pregnant women

Objective To investigate the effects of mifepristone ( RL486) and misoprostol on decidua of early pregnancy at the cellular level of estrogen receptor (ER) and progesterone receptor (PR) and hormone level in serum. Methods Sixty specimens of deciduas were obtained from early pregnant women with 6-7 weeks duration,of which 20 were normal pregnancy,20 were treated with mifepristone and 20 mifepristone plus misoprostol respectively. The level of ER and PR in decidua and hormone level in serum were compared among three groups by unmunohistochemistry and radioimmunoassay. Results The ER and PR level in human deciduas decreased after mifepristone plus misoprostol treatment. There were significant differences of the level of ER and PR among the three groups. In the group treated with mifepristone plus misoprostol,the concentrations of estradiol,testosterone and prolactin in serum were increased,while progesterone was decreased,but the level of follicular-stimulating hormone (FSH) and human chorionic gonadotropin (HCG) were not obviously affected. Conduskms Large doses of mifepristone competitively bind with progesterone receptor in decidua,which inteferes the combination of endogenous high-concentrated progesterone with its receptor in early pregnancy,so that the effect of terminating early pregnancy by mifepristone can be achieved.