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An animal hormone, C13H16N2O2, derived from serotonin and produced by the pineal gland. It stimulates color change in the skin of amphibians and reptiles and plays a role in regulating circadian rhythms and reproductive cycles in mammals. It is also found in plants and fungi.

[Greek melās, black + ton(e) + -in.]


(Biochemistry) the hormone-like secretion of the pineal gland, causing skin colour changes in some animals and thought to be involved in reproductive function
[C20: probably from mela(nocyte) + (sero)tonin]


(ˌmɛl əˈtoʊ nɪn)

a hormone secreted by the pineal gland in inverse proportion to the amount of light received by the retina, important in regulating biorhythms.
[1955–60; < Greek mélā(s) black + tone + -in1]


A hormone influencing the onset of puberty, the menstrual cycle, and the body’s daily activity cycle. See also pineal gland.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.melatonin - hormone secreted by the pineal gland
endocrine, hormone, internal secretion - the secretion of an endocrine gland that is transmitted by the blood to the tissue on which it has a specific effect


n melatonina
References in periodicals archive ?
Age-related changes in the rat brain mitochondrial antioxidative enzyme ratios: modulation by melatonin.
Recommend nightly melatonin 3 mg to your patients with chronic migraines, as it appears to be as effective as amitriptyline in reducing headaches and causes fewer adverse effects.
Present study aimed at evaluating the role of melatonin in extender for its cryoprotective effect on post-thaw quality of buffalo bull semen.
As daylight fades, the pineal gland produces a hormone called melatonin, which peaks at night and switches off again as day dawns.
Oral melatonin improved both sleep disturbance and skin symptoms in children and adolescents with atopic dermatitis (AD), in a study published in JAMA Pediatrics.
The latest compound to enter the marketplace is Rozerem, a melatonin agonist receptor.
In addition, melatonin promotes neurogenesis under diverse conditions, such as ovariectomy, pinealectomy, aging, or circadian disruption [17,34-40].
3 years) with mild-to-moderate Alzheimer's disease who were receiving standard therapy (acetylcholinesterase inhibitors with or without memantine) were randomly assigned to receive, in double-blind fashion, 2 mg of prolonged-release melatonin or placebo each night for 24 weeks.
In the past, we've shown you how melatonin can help you avoid dangerous drugs by getting rid of your heartburn naturally.
Popularized in the 1990s as a sleep aid, use of melatonin supplements is on the rise.
com, White Plains, NY, purchased a variety of popular melatonin supplements, testing them to be sure they contained the listed amounts of melatonin without unacceptable levels of lead contamination and that tablets would disintegrate properly to release ingredients.
The text discusses the use of melatonin in the treatment of certain neurodegenerative diseases.