Melatonin: the hormone that controls sleep and seasonal rhythms
It is a fact known to all that the human being, like all other animals, needs to sleep . Sleep is a basic physiological function, a mechanism that allows the organism (and especially the brain) to rest and repair itself. However, the dream is not a single and invariable process, but it goes through different phases throughout the process. In addition, it is a process that is not voluntary, but depends on circadian rhythms.
These rhythms regulate the sleep-wake cycle according to the biological needs of the organism and the time of day. Said regulation, as well as the seasonal patterns that occur in other animals, are mainly due to the action of a hormone: melatonin
Melatonin: what are we talking about?
Melatonin is a hormone secreted mainly by the epiphysis or pineal gland from tryptophan and serotonin. It is a very fat-soluble hormone, with great ease to penetrate the blood-brain barrier and inside the cells. This hormone is generated when the retina perceives absence of light, producing the maximum peak of this hormone during the night and reducing in the presence of luminosity.
The production process of melatonin is as follows: the retina captures the presence or absence of light, passing this information to the optic nerve, later to the suprachiasmatic nucleus and from there to the superior cervical ganglion, which reaches the epiphysis. This proceeds to perform a series of reactions that culminate in the production of melatonin, which is distributed by the rest of the body. Apart from its birth in the brain, it also appears in the retina, liver, kidneys, intestine, immune cells and in the female endometrium.
The melatonin receptors
Melatonin has its receptors at various points in the body , both inside and outside the brain, which produce different effects on the functioning of the body. Cerebral receptors of melatonin have an effect on circadian rhythms, non-neural receptors influence reproduction, and peripherals ultimately have different effects depending on their location.
In this way, the functions of melatonin are many and varied, affecting various systems of the organism, although the function by which more is known and studied is the control of circadian rhythms , carrying out mainly a chronobiological action in the suprachiasmatic nucleus. That is, this hormone helps to establish in what moments we go from sleep to wakefulness and vice versa. The maximum production usually occurs around an hour and a half after falling asleep, contributing to induce deep sleep.
Effects beyond the dream
Apart from the function of regulating the sleep-wake cycle, recent research has shown that this hormone has great utility in numerous systems. Actively participates in the regulation of seasonal and reproductive phenomena, such as zeal in animals. It also affects the long-term enhancement of memory .
The immune system is also affected by this hormone (reducing its efficiency during its absence) and having an important antioxidant effect that counteracts the excess of free radicals. Thus, this hormone also participates in the processes of growth and aging.
Use of melatonin exogenously
Despite being an endogenous hormone, manufactured by the body itself, melatonin has been synthesized artificially and has been marketed as dietary supplement (although it is not yet allowed as a medicine due to the little existing research and the inconclusive results extracted so far).
Some of the uses that have been given to him are the following:
1. Sleep disorders
Melatonin has been used as a treatment for sleep disorders . Specifically, it highlights its ability to improve sleep adjustment in cases of jet lag, demonstrating that administered around the time of sleep at the destination point the time mismatching decreases considerably. That is why it is widely used in circadian rhythm disorders. It also produces benefits for the delayed sleep phase syndrome, as well as sleep disorders in the case of individuals who work late at night.
However, in relation to primary insomnia or secondary to another disorder, although yes it has been shown to decrease sleep latency and improve the amount of sleep time , in some studies it has not shown an effect greater than placebo, being more effective the use of benzodiazepines and always prioritizing sleep hygiene.
Some investigations show that the administration of this substance produces improvement in other disorders due to the improvement in sleep patterns, being example of them cases of autism or infantile epilepsy. However, more research would be required in this regard.
- If you are thinking about buying melatonin to improve your rest, here we offer you a safe and effective product.
2. Action on reproduction and growth
It has been observed that the administration of melatonin is linked not only to sleep patterns, but also to other seasonal processes.
In animals, It has been proven that it affects and modulates periods of heat . In humans, it has been observed that the administration of this hormone affects growth, making it evident that it has an effect at the time of appearance of puberty. An excess of this hormone can delay it, while a defect can cause a breakthrough.
The research carried out indicates that melatonin supplementation can act preventively to prevent migraines .
4. Mood disorders
Different studies have shown the efficacy of the application of melatonin to improve the condition of patients with depressive disorders, especially in the case of seasonal affective disorder.
5. Aging and dementias
The production of melatonin is not constant throughout life , producing a significant and progressive decrease from adolescence to the end of life (which helps explain why the elderly have shorter and more frequent sleep periods).
In addition, much of the effects of aging are due to the presence of free radicals. Also, different types of free radicals and oxidation have also been linked to insane processes such as Alzheimer's or Parkinson's.
Given that it has been shown that melatonin is one of the greatest endogenous antioxidants available, several tests have been carried out that have shown that the administration of melatonin decreases oxidative damage in the different systems of the organism. can be helpful in delaying brain aging and prolonging intellectual functionality in demented pictures.
The application of melatonin in some patients with cancer seems to reduce tumor growth and prolong survival, being observed as a possible treatment to be combined with chemotherapy. This effect seems to be due to antiproliferative properties and to the potentiation of the effects of chemotherapy, especially in cases of cancers that depend on reproductive cells.
7. Other inconclusive investigations
As mentioned, melatonin has certain effects on the immune system, acting as a modulator . In addition to being a powerful antioxidant, it has been discovered that it acts on receptors in the T lymphocytes, contributing to the production of immunoglobulin.
The possibility that it contributes to slow the replication of HIV has been studied, so that it could be applied as a reinforcing treatment. Its usefulness in cases of different cancers has also been explored. However, the results are not conclusive.
- Benitez-King, G .; Ramirez-Rodriguez, G .; Ortiz, L. et al. (2004) The neuronal cytoskeleton as a potential therapeutic target in neurodegenerative diseases and schizophrenia. Curr Drug Targets CNS Neurol Disord; 3: 515-533.
- Boutin, J .; Audinot, V .; Ferry, G. and Delagrange, P. (2005). "Molecular tools to study melatonin pathways and actions." Trends Pharmacol Sci 26 (8): 412-9.
- Carrillo, A .; Guerrero, J.M .; Lardone, P.J. et al. (2005). A review of the multiple actions of melatonin on the immune system. Endocrine, vol. 27, 189-200.
- Dodick, D.W. & Capobianco, D.J. (2001). "Treatment and management of cluster headache". Curr Pain Headache Rep5 (1): 83-91
- Guerrero, J.M .; Carrillo, A. and Lardone, P. (2007). Melatonin Research and Science 30-38
- Martínez, B .; Sánchez, Y .; Urra, K .; Thomas, Y.D. & Burgos, J.L. (2012). Hormone of darkness. Rev Latinoamer Patol Clin, Vol. 59, 4, pp 222-232
- Lewis, A. (2006). Melatonin and the Biological Clock. New York, NY: Mc Graw-Hill; p. 7
- Portugal, F.L et al. (2010) Ação gives melatonin on apoptose and fator of vascular endothelial crescimento no cortex adrenal of pinealectomized rats. Rev Bras Ginecol Obstet. 32 (8).
- Reiter, R.J .; Tan, D.X .; Gitto, E. et al. (2004). Farmacological utility of melatonin in reducing oxidative cellular and molecular damage. Polish Journal of Pharmacology and Pharmacy, vol.56, 159-170.
- Reyes, B.M .; Velázquez-Panigua, M. and Prieto-Gómez, B. (2009). Melatonin and neuropathologies. Rev.Fac.Med. UNAM, Vol.52, 3. Genomic Sciences Center. Faculty of Medicine, UNAM.