Alternative names for kisspeptin
What is kisspeptin?
Kisspeptin is produced from the hypothalamus and causes a chain reaction which leads to production of neurotransmitters from the pituitary gland. The details of exactly how this happens are currently unknown, but might be linked to the changes in energy intake and use that occurs around adolescence (possibly via leptin and/or insulin). The neurotransmitter signals lead to the release of other hormones (luteinising hormone and follicle stimulating hormone) into the blood. These act on testes and ovaries to produce the sex hormones testosterone and oestradiol which cause the physical and emotional changes that are well recognised during puberty.
Kisspeptin has a non-hormonal role too and was originally named metastin after its ability to prevent the spread of cancer (metastasis).
How is kisspeptin controlled?
The precise control of kisspeptin release is still not fully understood. Testosterone and oestradiol prevent further luteinising hormone and follicle stimulating hormone release from the pituitary in a ‘fine tuning’ system known as a negative feedback loop. It is possible that testosterone and oestradiol act directly on neurones to prevent kisspeptin release or, alternatively, an unidentified chemical may be involved at some point in between.
What happens if I have too much kisspeptin?
It is not yet clear if having too much kisspeptin is good or bad, but a few small studies have linked high levels of kisspeptin during childhood to cases of (early) precocious puberty. More research is now needed to determine if this is the case.
What happens if I have too little kisspeptin?
When kisspeptin cannot act properly on its target cells in the body, it causes infertility in humans. A clinical trial has shown that giving kisspeptin to women with infertility and women who do not menstruate (a condition known as amenorrhoea) can restore the hormone levels in these conditions; however, further research is needed to determine whether this approach will be a useful new treatment for women with infertility.
Adolescents who have faulty kisspeptin signalling fail to undergo puberty (hypogonadotrophic hypogonadism) although this is a rare condition.
Recent evidence now suggests kisspeptin might play other roles in the body since it is also present outside the brain, eg, in the placenta and the cardiovascular system. For example, levels of kisspeptin in the blood go up massively (7,000 times!) during pregnancy although the reason why is not yet understood. Intriguingly, a few studies have shown that women who have less kisspeptin in the bloodstream early on in pregnancy may later develop pre-eclampsia, a condition which has serious consequences for both the mother (high blood pressure) and baby (growth restriction). It has been suggested by some that measuring kisspeptin during early pregnancy may be a useful screening tool to detect this condition earlier and hopefully lead to improved care. More research is now needed to determine if this is the case.
Written: March 2011