From Big Medical Encyclopedia

MELATONIN — N-acetyl-5-metoksitriptamin, hormone of an epiphysis (pinus). The clear morbid conditions connected with hyper - or M.'s hyposecretion, at the person it is not established, has no therapeutic use. The m at Amphibia and fishes takes part in coloring of skin and scales. Though function M. at mammals is studied a little, assume that it provides communication of an epiphysis with gipotalamo-pituitary system, and also with thyroid both gonads and adrenal glands.

For the first time M. was allocated in 1958 to Lernerom (A. V. with Lerner) from an epiphysis of a bull, in a year its chemical structure was established, and in a year it was having synthesized in laboratory. As well as serotonin (see), M. is derivative tryptophane (see).

The serotonin which is formed from 5 oxytryptophanes is acetylated with the participation of N-acetyltransferases enzyme, and further N-atsetilserotonin turns into M. This reaction is catalyzed an oxyindole-au-methyltransferase. Change of activity of these enzymes is the main mechanism of regulation of biosynthesis of M. Ustanovleno that M.'s synthesis is subject clearly to the expressed okolosutochny rhythms: considerably its bigger quantity is synthesized at night. On M.'s education at mammals, including and at the person, the great influence is exerted by a stress, Ektomiya's gonads, a menstrual cycle, sex steroid hormones.

M.'s catabolism occurs in a liver where it is hydroxylated, forms conjugates with sulfuric and glucuronic to-tami and is removed in the form of such connections with urine. See also Pinus .

Bibliography: Chazov E. I. and Isachenkov V. A. Epifiz, the place and a role in system of neuroendocrinal regulation, M., 1974, bibliogr.; Wurtman R. J., Axelrod J. and. To e 1 1 at D. E. The pineal, N. Y. — L., 1968.

B. A. Isachenkov.