부산대학교 도서관

Melatonin (N-acetyl-5-methoxytryptamine) represents the predominant hormone synthesized by the pineal gland, which is located at the posterior aspect of the third ventricle. Melatonin synthesis is mainly controlled by the light/dark environment. Retinal perception of light inhibits synthesis of melatonin, while darkness stimulates its production upon postsynaptic activation ofβ-adrenergic receptors. Owing to its nocturnal surge of synthesis, melatonin has gained popularity as the "hormone of darkness". Physiological roles of melatonin have been linked, among others, to modulation of the hypothalamic–pituitary–gonadal axis, onset of puberty and seasonal patterns of reproduction and breeding. Altered melatonin synthesis has been reported in a variety of disorders, including amenorrhea of anorectic and excessively exercising women, delayed onset of puberty, winter depression, asomnia, and jet lag (1). Further, lack of appropriate melatonin synthesis has been associated with sudden infant death syndrome, certain forms of breast cancer, premature ageing and cataract formation (1). Recently, novel actions of