P29, an oestrogen receptor-associated protein, is down- regulated by mifepristone in first trimester human placenta and decidua

P29 is an oestrogen receptor-associated protein which acts as a marker of oestrogen action in several systems. The concentration of P29 was measured in placenta and decidua from women following medical termination of pregnancy with the antiprogesterone steroid mifepristone (RU 38,486) and a prostaglandin E1 analogue, and compared with the concentration of P29 found in matched controls undergoing surgical aspiration of pregnancy. Oestrogen receptors were also measured in the same samples. Placental and decidual P29 concentrations (IU/mg protein) in patients treated with mifepristone were 9.6 (4.6-54) and 4.8 (1.3-13.3) (median and range), respectively. These values were significantly lower t…