Biphasic effect of gonadotropin releasing hormone on progestin secretion by rat granulosa cells

C. S. Sheela rani, C. Ekholm, H. Billig, C. Magnusson, T. Hillensjö

Research output: Contribution to journalArticlepeer-review

13 Scopus citations

Abstract

The effect of an agonistic gonadotropin releasing hormone (GnRH)-analog (D-Ala6, des-Gly10-NH2-GnRH-ethylamide, GnRHa) on granulosa cell steroidogenesis in the presence or absence of follicle-stimulating hormone (FSH) or luteinizing hormone (LH) was studied. Granulosa cells, isolated from preovulatory follicles of pregnant mare's serum gonadotropin (PMSG)-treated immature rats or from the less mature follicles of untreated immature rats, were cultured for a period of 72 h with daily changes of medium, and progesterone and its metabolite, 20α-dihydroprogesterone (20α-OHP), were assayed in the medium. In granulosa cells from preovulatory follicles, LH and FSH caused a much greater stimulation of steroidogenesis than did GnRHa. There appeared to be no interaction between GnRHa and FSH during the first 10 h, but at 24 h and later the presence of GnRHa clearly inhibited the steroidogenic response to LH and FSH. Steroidogenesis in granulosa cells from immature rats was considerably lower and the effects of GnRHa and FSH alone less pronounced. In these cells, FSH-stimulated progesterone secretion was inhibited by GnRHa only at 72 h. In contrast, 20α-OHP secretion in the same cultures was potentiated by the combined presence of FSH and GnRHa. In conclusion, it seems as though the effects of GnRHa on granulosa cell steroidogenesis vary with exposure time, the initial response being stimulatory and the later inhibitory. Furthermore, the response is also to some extent determined by the maturational stage of the granulosa cells.

Original languageEnglish (US)
Pages (from-to)591-597
Number of pages7
JournalUnknown Journal
Volume28
Issue number3
DOIs
StatePublished - Jan 1 1983
Externally publishedYes

ASJC Scopus subject areas

  • Reproductive Medicine
  • Cell Biology

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