It is an RFamide peptide that significantly reduced luteinizing hormone release in Coturnix Japonica (Japanese quail).
[2] GnIH is a neurohormone classified as an RFamide (RFa) or RFamide-related peptide (RFRP), coded by the NPVF gene in mammals.
[7] GnIH enters the bloodstream via the hypothalamo-hypophyseal portal system, the vascular network supplying both the hypothalamus and the pituitary.
GnIH also spurs the production of cytochrome P450 aromatase, promoting the synthesis of neuroestrogen in the brains of quails and reducing aggressivity in reproductive behaviors.
[20][21] These gonadal changes, in addition to GnIH and GnIH-R mRNA expression in the seminiferous tubules, Sertoli cells, and spermatogonia, implicate function in spermatogenesis.
In female vertebrates, high doses of GnIH increases ovarian mass and produce follicle irregularities, such as vacuole formation in nuclei and distorted morphology.
GnIH may therefore mediate interactions between the HPG and HPA (hypothalamic-pituitary-adrenal) axes and play a role in stress-related infertility.
[25] Furthermore, thyroid hormone may function in a pathway for photoperiodic regulation of reproduction involving GnIH and energy status.