Health

Blue-enriched white light to wake you up in the morning

Here is good news for those who have difficulty with morning alertness. A KAIST research team has proposed that a blue-enriched LED light can effectively help people overcome morning drowsiness. This study will provide the ...

Health

I can't sleep. What drugs can I (safely) take?

If you're having trouble sleeping, medicines shouldn't be your first option. Exercise regularly, cut back on coffee (and other caffeinated drinks) after midday, eat less in the evening, ease up on "screen time" before, and ...

Health

Evening use of light-emitting tablets may disrupt healthy sleep

A new Physiological Reports study reveals that evening use of light-emitting tablets can induce delays in desired bedtimes, suppress secretion of melatonin (the hormone that regulates sleep and wakefulness), and impair next-morning ...

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Melatonin

Melatonin i/ˌmɛləˈtoʊnɪn/, also known chemically as N-acetyl-5-methoxytryptamine, is a naturally occurring compound found in animals, plants, and microbes. In animals, circulating levels of the hormone melatonin vary in a daily cycle, thereby allowing the entrainment of the circadian rhythms of several biological functions.

Many biological effects of melatonin are produced through activation of melatonin receptors, while others are due to its role as a pervasive and powerful antioxidant, with a particular role in the protection of nuclear and mitochondrial DNA.

In mammals, melatonin is secreted into the blood by the pineal gland in the brain. Known as the "hormone of darkness," it is secreted in darkness in both day-active (diurnal) and night-active (nocturnal) animals.

It may also be produced by a variety of peripheral cells such as bone marrow cells, lymphocytes, and epithelial cells. Usually, the melatonin concentration in these cells is much higher than that found in the blood, but it does not seem to be regulated by the photoperiod.

Research has shown that when bird chicks ingest melatonin-rich plant feed, such as rice, the melatonin binds to melatonin receptors in their brains. No food has been found to elevate plasma melatonin levels in humans.

Products containing melatonin have been available over-the-counter as dietary supplements in the United States since the mid-1990s. In many other countries, the over-the-counter sale of this neurohormone is not permitted or requires a prescription, and the U.S. Postal Service lists unapproved melatonin preparations among items prohibited by Germany.

This text uses material from Wikipedia, licensed under CC BY-SA