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PubMed · 9842469

[Melatonin: hormone and medication].

Y Touitou
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Abstract

Melatonin (N-Acetyl-5-methoxytryptamine) is a hormone secreted mainly by the pineal gland or epiphyse and in smaller amounts by the retina. It is biosynthesized from tryptophan, the critical enzymatic step depends upon N-Acetyl-transferase (NAT). The circadian rhythm of melatonin is the same in man and all the laboratory animals studied until now with nocturnal plasma concentrations 3-10 times greater than during daytime. The secretion and release of melatonin depend upon a large number of exogenous and endogenous factors as e.g. sex, age, pubertal stage, menstrual cycle, drugs, season.... Light is the major regulating factor which acts through the retino-hypothalamic tract. Melatonin is considered as a transducer of the light signal forwarding to the organism the information about day length (relative length of day and night). It is a time-clue provider used by the organism to adapt itself to its environment.

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AcclimatizationAnimalsAnimals, LaboratoryCircadian RhythmFemaleHumansLightMaleMelatoninPineal GlandRetinaEnglish AbstractJournal ArticleReview

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Y Touitou. 1998. [Melatonin: hormone and medication].. https://pubmed.ncbi.nlm.nih.gov/9842469/

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