Follicular fluid of women with endometriosis stimulates the proliferation of endometrial stromal cells

The peritoneal environment in endometriosis is known to have growth-promoti ng effects on endometrial cells. To investigate whether follicular fluid, a contributor to the peritoneal fluid, stimulates endometrial cell prolifera tion, we incubated endometrial stromal cells in culture with various diluti ons of follicular fluid obtained from women with or without endometriosis u ndergoing oocyte retrieval for in-vitro fertilization. Cell proliferation a ssays were performed using follicular fluid from 28 women (without endometr iosis, n = 13; with endometriosis, n = 15) in eight different endometrial s tromal cell culture set-ups. Cell proliferation was assessed by a colorimet ric method. Maximum cell proliferation was detected when endometrial cells were incubated with 50% dilution of follicular fluid for 48 h, Follicular f luid from women with endometriosis induced significantly higher cell prolif eration than follicular fluid From women without endometriosis (P < 0.05). Our findings indicate that follicular fluid contents may contribute to the growth-promoting factors in the peritoneal fluid of women with endometriosi s.