Follicle-stimulating hormone and estradiol regulate antrum-like reorganization of granulosa cells in rat preantral follicle cultures.
Formation of a fluid-filled antrum results from the actions of FSH and estrogen on preantral ovarian follicles in most mammalian species. To investigate the novel proposal that hormone-regulated cell-cell interactions mediate antrum formation, we isolated preantral follicles from infant (10- or 11-day-old) Wistar rats and cultured them in a substratum-adherent manner in Minimum Essential Medium supplemented with 2 mM hypoxanthine, 3 mg/ml bovine serum albumin, 5 micrograms/ml insulin, 5 micrograms/ml transferrin, and 5 ng/ml selenium. Similar cultures were previously shown to support oocyte growth and acquisition of meiotic competence. In the absence of FSH, follicles attached to the plastic surface and granulosa cells spread-out uniformly around granulosa cell-enclosed oocytes. FSH treatment caused certain follicles to show an increase between culture days 3 and 7 in appearance of conspicuous antrum-like reorganization of the granulosa cells, but without forming a completely enclosed fluid-filled cavity. This response was biphasic over 10-500 ng/ml FSH, with an optimal concentration of 50 ng/ml resulting in a mean of 37.8 +/- 4.7% of follicles showing antrum-like reorganization for 3 similar experiments. Estradiol-17 beta alone at 10(-10)-10(-8) M was without effect on this response, but at 10(-10) and 10(-9) M, it significantly augmented the action of an optimal concentration of FSH by about 2-fold in 4 experiments. In these experiments, the effect of 10(-8) M estradiol was not significantly different from FSH alone, indicating that the response to estradiol was also biphasic.(ABSTRACT TRUNCATED AT 250 WORDS)
Gore-Langton
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Department of Physiology, University of Western Ontario, London, Canada.
Daniel
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D000818:Animals; D002450:Cell Communication; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D006107:Granulosa Cells / Q000187:drug effects*; D066298:In Vitro Techniques; D009024:Morphogenesis; D006080:Ovarian Follicle / Q000166:cytology / Q000187:drug effects; D010784:Photomicrography; D051381:Rats; D011919:Rats, Inbred Strains
D004958:Estradiol; D005640:Follicle Stimulating Hormone