Kisspeptin (neurotransmitter): how it works in the brain

Our bodies generate many substances and hormones, many of which are still a mystery to science. Every now and then, we discover different hormones and proteins that we didn’t know existed or what function they had until some research found them. And over time, these substances are studied more deeply and new properties are discovered.

This is what happened with the kisspeptin, A newly discovered hormone that is linked to inhibition of metastasis and the genesis of emotions related to affective and romantic bonds and sexual behavior.

    What is kisspeptin?

    Kisspeptin is a hormone observed from puberty on the hypothalamic-pituitary-gonadal axis of both sexes, and was discovered by a research team led by Lee in 1996 as part of research on cancer and its metastases. In fact, initially, it was called metastin because its discovery is associated with the removal of metastases. It was not until 2001 that he received his new name, after seeing the effect that his absence had on puberty.

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

    It is an endogenously generated substance, therefore being synthesized naturally by our body. It is secreted mainly in the hypothalamus and the hypothalamic-pituitary-gonadal axis, although it has also been found that this hormone is generated in large quantities in the placenta. Its function is based on its binding to its receptor, GPR54, which is linked to the G protein (which in turn acts as a transmitter of information from a particular receptor to other proteins).

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

    Kisspeptin he has a certain sexual dimorphism: At the level of the antero-ventral paraventricular nucleus, kisspeptin is much more present in women than in men (at least in experiments on rodents), reducing the massive exposure to androgens during pregnancy the levels of this hormone and of its receptors in this area.

    Functions in which this substance is involved

    Kisspeptin is a hormone that plays an important role in our body, performing different functions in different systems. Although many of them are unknown, among the best known and most studied, we can find the following.

    1. Awaken libido

    Kisspeptin is deeply linked to libido and sexual behavior, participating in the regulation of gonadal hormones. Indeed, 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 which generated romantic and erotic images.

    This alteration arises from the activation of neurons in the medial posterodorsal part of the amygdala (linked to sexual appetite), as well as from one of the main functions observed at the biological level: stimulate the secretion of gonadotropin releasing hormone. In fact, the high potential of this hormone to fight sexual dysfunction has been increased.

    This aspect has been observed primarily in men, requiring further research into the effects of kisspeptin on female sexual behavior. However, it has been observed to cause an increase in luteinizing hormone levels (although the level of increase depends on the period of the menstrual cycle in which it is administered).

    2. It promotes romanticism

    Kisspeptin not only has a positive effect on the sexual level, but has also been associated with an emotional component that makes it easier to experience romantic feelings and love, As well as the detection and appreciation of this.

      3. Helps regulate emotional response

      Research in humans shows that when faced with an injection of kisspeptin, it not only increases libido and romance, but also improves the regulation of negative emotions. It facilitates relaxation and management so as to reduce discomfort and stress. It is possible that it can be used as part of pharmacological treatment different mental disorders.

      4. Reduce anxiety

      Related to the previous point, kisspeptin is also linked to a decrease in the level of anxiety, having, as we have mentioned, effects on the amygdala. This aspect has been observed in several animal models, generating behavioral relaxation and lower stress levels. In humans, it could be associated with decreased anxiety in the various anxiety and obsessive disorders, as well as in this anxiety causing many cases of erectile dysfunction.

      5. It affects maturation and development

      A relationship has been found between kisspeptin and puberty, altering when it occurs. Administration of Kisspeptin stimulates the synthesis of gonadotropin releasing hormone and generates a advancing puberty. In women, it plays an important role in the initiation of the menstrual cycle.

      6. Inhibits or prevents metastasis

      In addition to its affective-sexual functions, kisspeptin is a hormone really relevant in the treatment of different types of cancer. And it has been observed that this hormone has a suppressive effect on metastasis of cancers such as breast, ovaries, kidneys, lungs and skin. In fact, the research in which this hormone was found is mainly related to this type of application.

      7. Participates in vasoconstriction

      It also has an effect at the vascular level, participating in vasoconstriction and finding a link between kisspeptin and arteriosclerosis.

      8. Contributes to the regulation of insulin levels

      Kisspeptin has been localized in the pancreas, participate in the synthesis and emission of insulin through the islets of Langerhans (In which kisspeptin can be found). There is research linking this hormone to diabetes.

      Bibliographical references:

      • Comninos, AN; Bloom, SR; Dhillo, WS et al. (2017). Kisspeptin modulates the sexual and emotional processing of the brain in humans. The Journal of Clinical Investigation, 127 (2): 709-719.
      • De Roux, N .; Genin, E .; Carel, J, C .; Matsuda, F .; Chaussain, JL and Milgrom, E, (2003). Hypogonadotropic hypogonadism due to loss of function of the peptide receptor derived from KiSS1 GPR54. PNAS, 100: 10972-10976.
      • Ricu Moya, M. (2013). Participation of kisspeptin in ovarian function and its modifications during the activation of the sympathetic nervous system induced by cold stress in rats. [Tesis doctoral, versión electrónica]. Available at http://www.repositorio.uchile.cl/handle/2250/113451
      • Mead, EJ; Maguire, JJ; Kuc, RE and Davenport, AP (2007). Kisspeptins are potent new vasoconstrictors in humans, with discrete localization of their receptor, the G-protein-coupled receptor 54, in atherosclerotic vessels. Endocrinology 148 (1): 140-7.
      • Song, WJ; Mondal, P .; Wolfe, A .; Alonso, LC; Stamateris, R .; Ong, BW; Lim, OC; Yang, KS; Radovick, S .; Novaira, HJ; Farber, EA; Farber, CR; Turner, SD; Hussain, MA (2014). Glucagon regulates hepatic kisspeptin to affect insulin secretion. Cell Metab. 19 (4): 667-681.

      Leave a Comment