Detailed definition
Gonadotropin-releasing hormone (GnRH), also called luteinizing hormone-releasing hormone (LHRH), is a 10-amino-acid peptide hormone produced by neurons of the hypothalamic preoptic area and arcuate nucleus. It is released in pulses into the hypothalamic-pituitary portal blood and binds GnRH receptors on pituitary gonadotropes, triggering the synthesis and release of FSH and LH. The pulsatile pattern is essential — continuous GnRH actually downregulates the receptor and shuts off gonadotropin release, which is the mechanism of GnRH agonist therapy. GnRH agonists (leuprolide, goserelin) and GnRH antagonists (cetrorelix, ganirelix, elagolix) are used clinically to suppress the HPO axis for endometriosis, uterine fibroids, central precocious puberty, fertility treatments, and hormone-sensitive cancers. The chemical menopause caused by GnRH agonist therapy is a useful experimental and clinical model for understanding menopausal symptoms in younger women.
Why it matters in menopause
For women on GnRH agonist therapy — for example, premenopausal breast cancer patients on goserelin or endometriosis patients on leuprolide — symptoms can be as severe as natural menopause, and add-back therapy with low-dose estrogen and progestin is sometimes used to manage them. Recognizing chemically induced menopause as biologically similar to natural menopause matters for treatment decisions about HRT in this population.
Related terms
Sources
External references: Wikipedia.