Serotonin tryptophan

Neurons manufacture serotonin in a series of chemical reactions, beginning with the amino acid tryptophan. Catalyzing these reactions are specific enzymes, such as an enzyme known as tryptophan hydroxylase, which speeds up a reaction that adds a hydroxyl group (an OH molecule) to tryptophan. Serotonin is packaged into vesicles, with each vesicle... 

C. Products derived from tryptophan —Serotonin, melatonin, and the nicotinamide moiety of NAD and... 

Nagendra SN, Shetty KT, Subhash MN, Udaya HB, Pradhan N (1993) Effect of disulfiram administration on brain tryptophan, serotonin and peripheral tryptophan content. Neurochem Int 22 31-36... 

Knapp et al.21 reported that the levels of forebrain tryptophan, serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), and hydroxylase cofactor (BH4) were comparable in two experimental mouse strains (A/J and C57B1/6J), despite two- to three-fold differences in vitro in the relative activities of forebrain and midbrain tryptophan-5-monoxygenase. The enzyme activities did not differ with respect to Km for cofactor at saturating levels, but manifested different degrees of cooperativity with respect to cofactor when examined with BH4 concentrations within a physiological range. 

Biggio, G., Fadda, F., Fanni, P., Tagliamonte, A., and Gessa, G. L., Rapid depletion of serum tryptophan, brain tryptophan, serotonin and 5-hydroxyindoleace-tic acid by a tryptophan-free diet, Life Sci., 14, 1321, 1974. 

Gessa et al.1 were the first to demonstrate that the acute administration of an amino acid mixture containing all of the essential amino acids, except tryptophan, caused a rapid fall in plasma free and total tryptophan in rats. Furthermore, this effect was associated with a parallel depletion in brain tryptophan, serotonin, and 5-hydroxyindole acetic acid in rats.2 These early studies opened the way for subsequent studies, using acute tryptophan depletion by feeding a tryptophan-free amino acid mixture, a simple, specific, and nontoxic method, to delete brain serotonin and thus provide a tool for clarifying the physiological role of serotonin in the central nervous system. 

Total citations on Medline for 5-year periods from 1961 to 2000. L-tryptophan = serotonin = and melatonin = . 

K.-H. van Pee, M. Holzer, in Tryptophan, Serotonin and Melatonin - Basic Aspects and Application. Advances in Tryptophan Research (Eds G. Huether, W. Koch, T. J. Simat,... 

Lit. Amino Acids 2, 181 (1992) (synthesis) FEBS Lett. 279, 145 (1991) (biosynthesis) Insect Biochem. 19, 673-678 (1989) Progress Tryptophan Serotonin Research,... 

TRYPTOPHAN, SEROTONIN, AND MELATONIN Basic Aspects and Applications Edited by Gerald Heuther, Walter Kochen, Thomas J. Simat, and Hans Steinhart... 

Hydroxytryptamine (serotonine), which occurs in both the animal and plant kingdom, is formed by hydroxylation and decarboxylation of tryptophan. Serotonine has attracted attention above all in human physiology. It is regarded along with adrenaline and acetylcholine as the third active substance in the transfer of the nerve stimulus in synapses or from nerve ends to the effector. 

Some amines are derived from tyramine (e. g., hordenine, synephrine, octopamine, dopamine and noradrenaline cf. Formula 18.3) and others from tryptophan (serotonin, tryptamine, melatonin Formula 18.4). The occurrence of... 

Tryptamine Tryptophan Serotonine, melatonine Locan tissue animal and plant hormones (catecholamines), effect on blood pressure, intestinal peristalsis, mental functions... 

EFFECTS OF FEEDING A LOW-PROTEIN DIET TO WEANLING RATS ON PLASMA TRYPTOPHAN AND BRAIN TRYPTOPHAN, SEROTONIN AND 5-HYDROXYINDOLE... 

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