Melatonin is a hormone secreted by the pineal gland. Production of melatonin is regulated via signals from the suprachiasmatic nucleus, the seat of a mammal’s circadian clock. Thus, melatonin levels are highest during the hours of darkness, and lowest during the day (i.e. light). Exogenously administered melatonin elicits a sleep promoting effect, although owing to interaction with the fluctuations of endogenous melatonin, this effect is highly dependent on the time of day the compound is ingested. Nevertheless, a synthetic compound that acts as an agonist at melatonin receptors (ramelteon) has been shown clinically to be useful as a hypnotic. Endogenously, in addition to its role in the circadian cycle, melatonin acts as an antioxidant and immunoregulator.
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© 2008 Springer-Verlag Berlin Heidelberg New York
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(2008). Melatonin. In: Offermanns, S., Rosenthal, W. (eds) Encyclopedia of Molecular Pharmacology. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-38918-7_6139
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DOI: https://doi.org/10.1007/978-3-540-38918-7_6139
Publisher Name: Springer, Berlin, Heidelberg
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