GC: n
S: NCBI – https://bit.ly/31yDJO7 (last access: 10 August 2019); WebMD – https://wb.md/2HkWdZq (last access: 10 August 2019).
N: 1. Chemical formed in the pineal gland of mammals that regulates certain physiological activities, 1958, from Greek melas “black, dark” (see melano-) + ending from “serotonin”. So called because its secretion is inhibited by sunlight, or because it changes the skin color of certain reptiles and amphibians.
2. Melatonin, hormone secreted by the pineal gland, a tiny endocrine gland situated at the centre of the brain. Melatonin was first isolated in 1958 by American physician Aaron B. Lerner and his colleagues at Yale University School of Medicine. They gave the substance its name on the basis of its ability to lighten skin colour in frogs by reversing the skin-darkening effects of melanocyte-stimulating hormone. Melatonin, a derivative of the amino acid tryptophan, is produced in humans, other mammals, birds, reptiles, and amphibians.
3. In humans, melatonin plays an important role in the regulation of sleep cycles (i.e., circadian rhythm). Its production is influenced by the detection of light and dark by the retina of the eye. For example, the production of melatonin is inhibited when the retina detects light and is stimulated in the absence of light. Special photoreceptor cells in the retina send signals about light status to the suprachiasmatic nucleus (SCN) in the hypothalamus of the brain. These signals are then transmitted to the pineal gland. Melatonin generation by the pineal gland, which peaks during the nighttime hours, induces physiological changes that promote sleep, such as decreased body temperature and respiration rate. During the day, melatonin levels are low because large amounts of light are detected by the retina. Light inhibition of melatonin production is central to stimulating wakefulness in the morning and to maintaining alertness throughout the day.
4. 5-methoxy-N-acetyl tryptamine, a hormone synthesized by the pineal gland, which produces marked lightening of dermal pigmentation in amphibians by stimulating the aggregation of melanosomes in melanophores, and inhibits gonad development and influences estrus in mammals.
5. Used as a food supplement products.
S: 1. OED – https://bit.ly/2KDuPrF (last access: 10 August 2019). 2 & 3. EncBrit – https://bit.ly/2KqcKhW (last access: 10 August 2019). 4 & 5. TERMIUM PLUS – https://bit.ly/2ZQ6Zzc (last access: 10 August 2019).
SYN: 5-methoxy-N-acetyl tryptamine
S: TERMIUM PLUS – https://bit.ly/2ZQ6Zzc (last access: 10 August 2019)
