title: Estrogen regulation of follicle stimulating hormone in cell cultures of sheep pituitaries.
abstract: Cell cultures of ovine pituitaries were maintained for up to 3 weeks. A specific double antibody radioimmunoassay was used to measure FSH in the media and cells. The rate of FSH synthesis increased in the cultures during the first 4-6 days to a level of approximately 50 ng/day/106 cells, generally remained constant for 2 weeks and then decreased. The FSH produced in vitro migrated similarly to highly purified ovine FSH on P-60 polyacrylamide gel filtration columns and had a biological potency essentially identical to that of the highly purified FSH standard. Addition of 17beta-estradiol (E2) at 10-9M on days 2 or 6 incubation decreased FSH synthesis greater than 95% within 30 h. Time-course analysis revealed that the effect of E2 can be observed as early as 6 h after treatment. FSH synthesis resumed after removal of E2 and reached control levels within 6 days. The lowest effective dose of E2 was 10-11M; E2 at 5 X 10-11M maintained FSH production at approximately 50% of the control levels. Diethylstilbestrol was as active estriol was 1/10th as active and 17alpha-estradiol was 1/100th as active as E2. Progesterone (P), 5alpha-pregnane-3,20-dione (5alphaDHP), 20alpha-hydroxy-pregn-4-en-3-one(20alpha-OHP), testosterone, 5alpha-dihydrotestosterone and corticosterone had no effect on FSH levels. These findings suggest that estrogen is capable of playing a major role in FSH synthesis and release by action directly at the pituitary level.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D005640:Follicle Stimulating Hormone / Q000096:biosynthesis*; D010902:Pituitary Gland / Q000378:metabolism*; D012756:Sheep; D013997:Time Factors
chemical_list: D004958:Estradiol; D005640:Follicle Stimulating Hormone