Kisspeptin is a neuropeptide produced by cells of the hypothalamus and is important in the regulation of hormones that control fertility. It controls the release of a gonadotropin-releasing hormone (GnRH) that stimulates the production and secretion of Luteinizing Hormone (LH). LH is then released from the pituitary gland and acts on Leydig cells within the testis to produce testosterone. Kisspeptin has been shown to increase testosterone in males experiencing low T levels.
In addition to regulating fertility, kisspeptin is also a tumor suppressor. Danny Welch in his lab in Hershey, Pennsylvania (the home of Hershey’s Kisses) was able to introduce a chromosome from a non-metastatic cancer cell into a metastatic tumor and found that the metastatic cells were no longer able to metastasize. He then isolated the cDNA for a gene that was involved in this process and named it KISS1. Kisspeptin is also known to have a direct role in the regulation of metabolism. In a study on rhesus monkeys kisspeptin administration was able to boost luteinizing hormone and adiponectin, which helped reduce blood glucose levels and metabolize fat more efficiently.
In some rare cases, kisspeptin activity in the hypothalamus is disrupted due to genetic mutations and results in early puberty, sometimes referred to as precocious puberty. Disruption of this pathway leads to a lack of GnRH and thus LH and testosterone (men) or oestradiol (women). Kisspeptin has been shown to be effective in stimulating the secretion of these hormones in children with this condition, as well as being an alternative to current IVF treatment methods that can cause ovarian hyperstimulation syndrome.