MOLECULAR MECHANISMS OF GONADOTROPIN-RELEASING HORMONE-STIMULATED GONADOTROPIN-SECRETION

Hypothalamic gonadotrophin releasing hormone (GnRH) exerts its effect on gonadotrophin synthesis and release via plasma membrane-bound recep tors. The exocytosis of luteinizing hormone (LH) and follicle-stimulat ing hormone (FSH) is activated by the binding of GnRH or its agonists to receptors in pituitary cells, which initiates a number of post-rece ptor events within the gonadotroph cell. Various potential second mess engers have been claimed to mediate the stimulatory action of GnRH inc luding calcium, inositol phosphates, protein kinase C, arachidonic aci d metabolites and cyclic nucleotides. It appears that more than one of these pathways is required to fully mimic the GnRH effect.