Interaction of estrogen and gonadotrophins on follicular atresia.
We have investigated folluclar atresia by giving hypophysectomized immature female rats (HIFR) diethylstibestrol or gonadotrophins with and without the chemical antiestrogen CI-628, making total counts of normal and atretic follicles greater than 125 muM in diameter, and using a simple model to analyze data. Our results show an antiatretic effect of estrogen, independent of its well-documented mitogenic effect on preantral follicles. We have also shown that CI-628 acts as an anti-estrogen to block follicular proliferation, while acting as an estrogen to inhibit atresia. In addition, we have observed an increase in atresia caused by gonadotrophins, in opposition to their estrogen-mediated positive effect on follicular growth.
D000818:Animals; D002452:Cell Count; D002455:Cell Division / Q000187:drug effects; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D004054:Diethylstilbestrol / Q000494:pharmacology; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D006062:Gonadotropins / Q000494:pharmacology*; D007016:Hypophysectomy; D009594:Nitromifene / Q000494:pharmacology; D009929:Organ Size / Q000187:drug effects; D006080:Ovarian Follicle / Q000187:drug effects*; D051381:Rats
D006063:Chorionic Gonadotropin; D006062:Gonadotropins; D009594:Nitromifene; D004054:Diethylstilbestrol; D005640:Follicle Stimulating Hormone