Kisspeptin

Kisspeptin is a family of neuropeptides encoded by the KISS1 gene, with Kisspeptin-10 being the shortest biologically active fragment. Originally discovered as a metastasis suppressor (hence the name Metastin), kisspeptin was later identified as a critical regulator of reproductive function through its role in stimulating gonadotropin-releasing hormone (GnRH) secretion from the hypothalamus.

Kisspeptin acts by binding to the GPR54 (KISS1R) receptor on GnRH neurons in the hypothalamus, triggering GnRH release which in turn stimulates the anterior pituitary to secrete luteinizing hormone (LH) and follicle-stimulating hormone (FSH). This places kisspeptin at the apex of the reproductive hormone cascade. Loss-of-function mutations in either KISS1 or KISS1R result in hypogonadotropic hypogonadism, confirming its essential role in reproductive function.

Clinical research has explored kisspeptin's potential in fertility treatment, particularly in IVF protocols where it may offer a safer alternative to hCG for triggering oocyte maturation with lower risk of ovarian hyperstimulation syndrome. Studies have demonstrated its ability to robustly stimulate LH secretion in both men and women, with potential applications in diagnosing and treating disorders of puberty, infertility, and hypothalamic amenorrhea. Research at Imperial College London has also shown that kisspeptin enhances brain processing of sexual and romantic stimuli.