ChEBI: A member of the class of acetamides that is acetamide in which one of the hydrogens attached to the nitrogen atom is replaced by a 2-(5-methoxy-1H-indol-3-yl)ethyl group. It is a hormone secreted by the pineal gland in humans.
Synthesis of Melatonin
Pineal cells obtain tryptophan from blood circulation and become 5-hydroxytryptophane catalyzed by hydroxylase and 5-hydroxytryptophane turns into 5-hydroxytryptamine after decarboxylated by decarboxylase. There are three possible changes for 5-hydroxytryptamine: for the first part it may turn into 5-hydroxyl-benzpyrole acetic acid when deaminated by monoamine oxidase; for another part, some 5-hydroxytryptamine will leave the pineal cell and be taken in by sympathetic nerve ending and stored with neurotransmitter and noradrenalin; for the remaining part, the 5-hydroxytryptamine will be acetylated by N-acetyl-5-hydroxy tryptamine transferase and then be o-methoxy by hydroxylation indole-o-methyl converzyme, finally forming melatonin. After being synthesized, melatonin will be released by cells and enter into blood circulation through cerebrospinal fluid or directly, where noradrenalin may strengthen the synthesis, the speed of which depends on activity of hydroxylase in liver microsomes. Catalyzed by the hydroxylase, 6-hydroxylmelatonin is formed, soon afterwards it combines with glucuronic acid and sulfate, excreting through urine.
1. The effect to brain: the melatonin obtained by brain mainly gathers in midbrain and hypothalamus and it adds the activity of brain pyridoxal kinase, thus promoting glutamic acid decarboxylation to γ-amino butyric acid, 5-hydroxytryptophane decarboxylation to 5-hydroxytryptamine, both of which can inhibit the increase of the neurotransmitter content and have an effect of adjustment and mitigation on central nervous system.
2. The effect to hypothalamus and pituitary: materials like polypeptide produced by pineal body still have thyrotropin-releasing hormone(TRH) and luteinizing hormone releasing hormone(LRH) which are same with what hypothalamus produces except AVT. After injection of melatonin, gonadotropin (GnH)(FSH,LH) and melanocyte stimulating hormone(MSH) are lowered while growth hormone increases. Cutting pineal gland will cause pituitary hypertrophy, increase pituitary secretion and lower prolactin(PRL) and antidiuretic hormone (ADH).
3. The relation to gonad: melatonin has an inhibitory effect on the reproductive system. Clinically, main cytoma of pineal body can lead to pubertal delay and when teratoma appears in pineal body, it may result in sexual precocity because main cells are excluded. Ambient light and sympathetic nerve can affect the function of the reproductive system by inhibiting the synthesis and release of melatonin in pineal gland.
4. The relation to thyroid: by injecting melatonin, thyroid secretion will decrease. This may be caused through the inhibition of the hypothalamus release and Thyroid Stimulating Hormone (TSH) secretion of pituitary, hence holding back the function of thyroid.
5. The relation to adrenal cortex: melatonin has a strong inhibitory effect on adrenal cortex. If we inject pineal body extracts to healthy people, we will find that their aldosterone secretion and 17-ketosteroid output will decrease.
6. The relation to pancreatic island: melatonin can lower blood glucose and increase sugar tolerance. In conclusion, pineal gland can assist pituitary to jointly adjust endocrine function and play an vital role in keeping relatively constant in body environment and controlling some endocrine function, especially for gonad.
Melatonin is a hormone secreted by the pineal gland, and its chemical structure was 5-methoxy-N-acetyl tryptamine, the physiological function of inhibiting gonad, thyroid, adrenal gland, parathyroid gland and pituitary function, inhibit precocious puberty, reduce pituitary Melanotropin secretion; and has a central nervous system function, can improve the convulsion the threshold, cause drowsiness. When pinealectomy after the animal experiment showed hyperplasia of the glands, weight increase, especially sex and sexual organs of immature rats early, pituitary secretion of LH and FSH increased, increasing secretion of thyroid and adrenal cortex hormone melatonin. More reduced pituitary MSH and whiten the skin of this role. Effects on the central nervous system, in the human EEG showed slow rhythm, increased seizure threshold, sleepiness, but does not affect their behavior and personality, of temporal lobe epilepsy and Ba Jinsen disease can reduce the motor nerve Abnormal EEG changes.
sleep induction, modifies circadian rhythm, antioxidant, free radical scavenger
1. Melatonin can be used as medicine health care products, so as to enhance people’s immune function, preventing aging and back to youth. What’s more, it is also a kind of natural “sleeping pill”.
2. Melatonin is a kind of hormone secreted by pineal body of pituitary gland in the body. The amount of melatonin has something to do with light. The weaker the light is, the more the melatonin is, whereas the less. In addition, it is helpful to one’s sleep.
3. Biochemical research.
White or almost white crystalline powder.
Hormone; mediates photoperiodicity in mammals; inhibits cerebellar nitric oxide synthetase; peroxynitrite scavenger. Melatonin has complex effects on apoptotic pathways, inhibiting apoptosis in immune
cells and neurons but enhancing apoptotic cell death of cancer cells. Inhibits proliferation/metastasis of breast cancer cells by inhibiting estrogen receptor action.
Immunostimulant;Melatonin receptor ligand
Hormone postulated to mediate photoperiodicity in mammals. Inhibits cerebellar nitric oxide synthetase
Endogenous hormone that acts as an agonist at melatonin receptors MT 1 and MT 2 . Exhibits a prominent role in the control of circadian rhythm, displays immunomodulatory activity and acts as a powerful antioxidant in vivo .