Effect of in vivo GnRH agonist and GnRH antagonist on hCG and insulin-stimulated progesterone production by human granulosa-lutein cells in vitro.
OBJECTIVE
To investigate hCG and insulin-stimulated progesterone (P) production by human granulosa-lutein cells (hGLC) in vitro.


METHODS
hGLCs were isolated from patients undergoing IVF-ET cycles in which GnRH agonist or GnRH antagonist was used to prevent a midcycle gonadotropin surge. The cells were cultured for 3 days, and then treated with hCG 0.5, 1, and 10 IU/I, and insulin 0.01, 0.1, and 1 microM in serum free conditions. In vitro P production was measured by enzyme immunoassay.


RESULTS
hCG stimulated P production by hGLCs from cycles in which GnRH antagonist was used, but a blunted response was seen in GnRH-agonist treated cycles. Insulin-stimulated P production was similar in cells from cycles in which GnRH-agonist or GnRH-antagonist treatment was used.


CONCLUSIONS
Because insulin and hCG may share common pathways beyond the level of receptor activation, we hypothesize that GnRH agonist, but not GnRH antagonist, may affect the expression and/or activation of LH receptors in the hGLCs.
Department of Obstetrics and Gynecology, Samuel Lunenfeld Research Institute and Mount Sinai Hospital, University of Toronto, Ontario, Canada.
Mohamed F M
MF
Mitwally
Robert F
RF
Casper
D000328:Adult; D006063:Chorionic Gonadotropin / Q000378:metabolism; D005260:Female; D005300:Fertility Agents, Female / Q000494:pharmacology*; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology*; D006727:Hormone Antagonists / Q000494:pharmacology*; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D016729:Leuprolide / Q000494:pharmacology*; D008184:Luteal Cells / Q000187:drug effects / Q000378:metabolism*; D010062:Ovulation Induction / Q000379:methods*; D011374:Progesterone / Q000096:biosynthesis*
D006063:Chorionic Gonadotropin; D005300:Fertility Agents, Female; D006727:Hormone Antagonists; D007328:Insulin; D007987:Gonadotropin-Releasing Hormone; D011374:Progesterone; D016729:Leuprolide; C061018:ganirelix