There are multiple substances and hormones that our body generates, many of which are still a mystery to science. From time to time we find different hormones and proteins that we did not know existed or the function that they possessed until certain investigation finds them. And over time, these substances are investigated in greater depth and new properties of these are discovered.

This is what happened with kisspeptine , a recently discovered hormone that is linked to the inhibition of metastasis and the genesis of emotions related to affective-romantic bonding and sexual behaviour.

What is kisspeptine?

Kisspeptine is a hormone that has been observed from puberty in the hypothalamus-pituitary-gonadal axis of both sexes, and was discovered by a research team led by Lee in 1996 within the framework of research into cancers and their metastases. In fact, was initially called metastine because its discovery was associated with the suppression of metastases . It would not be until 2001 that it would receive its new name, after seeing the effect that its absence generates on the arrival of puberty.

The term kisspeptine actually refers to a set of different peptides derived from a common precursor to all of them and which is encoded by the Kiss1 gene.

It is a substance generated endogenously, being therefore synthesized in a natural way by our organism. It is mainly secreted in the hypothalamus and the hypothalamus-hypophyse-gonadal axis, although it has also been discovered that this hormone is generated in large quantities in the placenta. Its functioning is based on its binding to its receptor, GPR54, which is attached to the G-protein (which in turn acts as a transmitter of information from a particular receptor to other proteins).

The receptors of this hormone have been found distributed throughout the brain and nervous system, although it is possible to find a much more massive concentration in the anteroventral and arcuato nuclei of the same structure that seems to generate it, the hypothalamus. It also appears in the spinal cord, in the preoptic nucleus and in the medulla, being associated with sexual response. Pancreas, adrenal cortex, liver, gonads and blood vessels are other structures in which it has been located, producing different effects.

Kisspeptine has a certain sexual dimorphism : at the level of the anteroventral paraventricular nucleus, kisspeptine is much more present in females than in males (at least in experimentation with rodents), reducing the massive exposure to androgens during gestation and the levels of this hormone and its receptors in that area.

Functions involving this substance

Kisspeptine is a hormone with an important role in our body, exerting different functions in different systems. Although many of these are unknown, the following are among the best known and most researched.

1. Awaken the libido

Kisspeptine is deeply linked to libido and sexual behavior, participating in the regulation of gonadal hormones. In fact, it has been observed that injections of this hormone generate in male mice a higher level of attraction towards females of the same species, generating a higher level of interaction between them and producing a rapprochement. In humans it has been shown that increases the level of excitement and the level of attraction that generated romantic and erotic images.

This alteration comes from the activation of the neurons of the medial posterodorsal part of the amygdala (linked to sexual appetite), as well as due to one of the main functions observed at the biological level: stimulating the secretion of gonadotropin-releasing hormone . In fact, the high potential of this hormone to combat sexual dysfunctions has been raised

This aspect has been observed mainly in men, and more research is needed on the effects of kisspeptine on female sexual behaviour. However, it has been observed to cause an increase in LH levels (although the level of increase depends on the time of the menstrual cycle at which it is administered).

2. Encourages romanticism

Not only does kisspeptine have a positive effect on the sexual level, but it has also been associated with an emotional component that facilitates the experience of romantic feelings and love , as well as the detection and appreciation of it.

3. Helps to regulate emotional response

Research with human beings shows that an injection of kisspeptine not only increases libido and romanticism but also enhances the regulation of negative emotions. It facilitates relaxation and management in a way that reduces discomfort and stress. The possibility is raised that it can be used in the pharmacological treatment of different mental disorders.

4. Reduces anxiety

Linked to the previous point, kisspeptine is also linked to a reduction in the anxiety level, having as we have commented effects on the amygdala. This aspect has been observed in several animal models, generating a relaxation of the behavior and less elevated levels of stress. In humans, this could be associated with a decrease in anxiety in the different anxiety and obsessive disorders, as well as that anxiety that causes many cases of erectile dysfunction.

5. Affects maturation and development

A link has been found between kisspeptine and puberty, changing the timing of the occurrence. The administration of kisspeptine stimulates the synthesis of gonadotropin-releasing hormone and generates an early entry into puberty . In women, it plays an important role at the beginning of the menstrual cycle.

6. Inhibits or hinders metastasis

In addition to its functions in the affective-sexual field, kisspeptine is a hormone really relevant in the treatment of different types of cancer . It has been observed that this hormone has a suppressive effect on metastasis from cancers such as breast, ovarian, kidney, lung and skin. In fact, the research in which this hormone was found is mainly linked to this type of application.

7. Participates in vasoconstriction

It also has an effect at the vascular level, participating in vasoconstriction and finding some link between kisspeptine and atherosclerosis.

8. Contributes to the regulation of insulin levels

Kisspeptine has been located in the pancreas, participating in the synthesis and release of insulin through the islets of Langerhans (where kisspeptine can be found). There is some research linking this hormone to diabetes.

Bibliographic references:

  • Comninos, A.N.; Bloom, S.R.; Dhillo, W.S. et al. (2017). Kisspeptin modulates sexual and emotional brain processing in humans. The Journal of Clinical Investigation, 127 (2): 709-719.
  • De Roux, N.; Genin, E.; Carel, J,C.; Matsuda, F.; Chaussain, J.L. & Milgrom, E, (2003). Hipogonadismo hipogonadotrópico debido a la pérdida de función del receptor peptídico GPR54 derivado del KiSS1. PNAS, 100: 10972-10976.
  • Ricu Moya, M. (2013). Participación de kisspeptina en la función ovárica y sus cambios durante la activación del sistema nervioso simpático inducido por el estrés por frío en la rata. [Tesis doctoral, versión electrónica]. Disponible en http://www.repositorio.uchile.cl/handle/2250/113451
  • Mead, E.J.; Maguire, J.J.; Kuc, R.E. y Davenport, A.P. (2007). Las bespeptinas son nuevos y potentes vasoconstrictores en los seres humanos, con una localización discreta de su receptor, el receptor 54 acoplado a la proteína G, en los vasos propensos a la aterosclerosis. Endocrinología 148 (1): 140-7.
  • Song, W.J.; Mondal, P.; Wolfe, A.; Alonso, L.C.; Stamateris, R.; Ong, B.W.; Lim, O.C.; Yang, K.S.; Radovick, S.; Novaira, H.J.; Farber, E.A.; Farber, C.R.; Turner, S.D.; Hussain, M.A. (2014). El glucagón regula la bespeptina hepática para impedir la secreción de insulina. Metabólico celular. 19 (4): 667-681.