Gonadotropin  inhibitory  hormone  (GnIH)  prevents the ‘priming’ effect of estradiol-17β

Ika Puspita Sari; Jessica Jacobi; Alexandra Rao; Iain Clarke

doi:10.14499/indonesianjpharm0iss0pp166-173

Gonadotropin inhibitory hormone (GnIH) prevents the ‘priming’ effect of estradiol-17β

Ika Puspita Sari, Jessica Jacobi, Alexandra Rao, Iain Clarke

Abstract

GnIH inhibits GnRH-stimulated gonadotropin secretion in the sheep by action on the pituitary gonadotropes. Estradiol-17β(E2) also acts at the level of the pituitary gonadotrope to exert negative and positive feedback effects on gonadotropin secretion. The positive effect facilitates the estrogen-induced surge in gonadotropin releasing hormone (GnRH) and LH. This study was undertaken to determine whether this ‘priming’ effect of E₂ is prevented by GnIH. Cultured pituitary cells were treated with GnRH or vehicle every 4 h for 24 h with and without GnIH and E₂ treatment. GnRH stimulated (LH) and follicle stimulating hormone (FSH) secretion was increased by E₂ treatment. The effect of E₂ was overcomes by the inhibitory effect of GnIH. We conclude that GnIH may counteract the priming effect of E₂ on pituitary gonadotropes.

Key words:Gonadotropin, gonadotrope, gonadotropin inhibitoryhormone, estradiol

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References

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DOI: http://dx.doi.org/10.14499/indonesianjpharm0iss0pp166-173