Pineal hormone melatonin

In addition to its presumed role as a neurotransmitter within the brain, serotonin is synthesized in the pineal gland, where it is a precursor for the synthesis of melatonin, a hormone that influences endocrine activity, presumably by an action within the hypothalamus. 

Melatonin—A hormone produced by the brain s pineal gland and thought to promote sleep. 

Serotonin is synthesized via tryptophan and 5-hydroxytryptophan with decarboxylation of the latter (Fig. 25-12). Within the pineal body of the brain and in the retina, serotonin is acetylated to N-acetylseroto-nin,782/783 which is then O-methylated to melatonin, the pineal hormone (Fig. 25-12). A specific inhibitor of serotonin synthesis is p-chlorophenylalanine, and studies with this and other inhibitors suggest that serotonin is required for sleep.784... 

The pineal gland appears also to play a role in maintaining the mammalian circadian cycle.1081-1083 The concentration of the pineal hormone melatonin (Fig. 27-11) as well as its precursor N-acetylserotonin and the enzyme serotonin N-acetyltransferase (Eq. 30-4) all fluctuate far more than do the concentrations of other metabolites during the 24-h cycle. These metabolites increase over 10-fold concentration at night and decrease by day. During the daytime the serotonin N-acyltransferase, which forms the precursor, is rapidly... 

In patients with DSPS, a delay in the timing of physiological and behavioral systems that demonstrate circadian rhythmicity is reported, compared to normally entrained individuals. This delay is evident in a variety of functions, including secretion of the pineal hormone melatonin (e.g., Ref. 162), thermoregulation, and sleep-wake activity. Individuals with DSPS typically experience difficulty initiat-... 

Suzuki S, Dennerstein L, Greenwood KM, Armstrong SM, Sano T, Satohisa E. Melatonin and hormonal changes in disturbed sleep during late pregnancy. J Pineal Res 1993 15 191-198. 

Dubey V, Mishra D, Asthana A, Jain NK (2006) Transdermal delivery of a pineal hormone melatonin via elastic Uposomes. Biomaterials 27(18) 3491-3496... 

Melatonin, a hormone of the pineal gland which is responsible for the circadian rhythms, is also a strong antioxidant in vitro. However, the concentrations of this hormone in vivo are far below the effective range. 

The pineal gland appears also to play a role in maintaining the mammalian circadian cyde. The concentrahon of fhe pineal hormone melatonin (Fig. 27-11) as well as its precursor N-acetylserotonin and the enzyme serotonin N-acetyltransferase (Eq. 30-... 

Melatonin, a hormone secreted in the light-sensitive pineal gland in the vertebrate brain, is thought to function in the formation of biological rhythms (Campbell et al., 1999). Melatonin is... 

Melatonin, a hormone secreted by the pineal gland that regulates circadian rhythms, including wake-sleep cycles, is biosynthesized by a process in which the first step is an enzyme-catalyzed transfer of the acetyl group from sulfur of acetyl coenzyme A to the —NH2 group of serotonin. 

The pineal hormone melatonin inhibits the production of free radicals that mediate the toxicity of chemotherapy. The main objective of this prototype drug-deHvery system was to develop and evaluate a novel occlusive bioadhesive system for prophylaxis and/or treatment of oral mucositis based on chitosan, melatonin and propoHs in order to exploit natural biomaterials as functional biocompatible gels [35,40],... 

However, despite its enormous importance to human physiology, no pharmacological compounds targeting the components of the circadian clock system have been identified to date. There are, nevertheless, two therapeutic approaches that are currently used for treatment of circadian-related disorders - full-spectrum and bright light therapy and melatonin therapy. Melatonin is a hormone that is produced by the pineal gland in... 

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