出典:Wikipedia
出典:『Wikipedia』 (2011/06/14 15:03 UTC 版)
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.