Effect of antiprogestin RU 486 on the proliferation and metabolic activity of stromal cells separated from human endometrium

Abstract The effects of RU 486 on the proliferation and metabolic activity of human endometrial stromal cells in culture were studied. RU 486 at 10 −7 M/well significantly stimulated (P −6 M/well did not stimulate metabolic activity in the culture. Progesterone, in combination with RU 486 at 10 −7 M/well, caused a significant increase in proliferation (assessed by thymidine incorporation) (P 4 alone, but not significantly different from RU 486 at 10 −7 M/well alone. The same pattern was observed for metabolic functions (assessed by uridine incorporation) when RU 486 at 10 −7 M/well, along with P 4 , was added to the culture. Interestingly, RU 486 at 10 −6 M/well with P 4 had no effect on RNA synthesis in the culture. The relevance of these findings is discussed.