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5-HTP (5-hydroxytryptophan)

Serotonin, or 3-(beta-aminoethyl)-5-hydroxyindole (5-hydroxytryptophan, or 5-HT) is a neurotransmitter in the central nervous system which is known to play an important role in the pathogenesis of affective illness. Serotonin acts through specific cellular receptors that comprise at least 15 individual subtypes. These receptors can be grouped into at least four families based on structural and functional characteristics. The 5-HT1, 5-HT2 and 5-HT4 families are G-protein coupled receptors linked to enzymatic and electrical effector systems, while the 5-HT3 receptor is a gated ion channel. The brain neurotransmitter, serotonin, appears to influence both energy balance and the circadian patterns of eating by activating satiety neurons in the medial hypothalamus. Serotonin seems to interact antagonistically with norepinephrine, resulting in decreased appetite and carbohydrate consumption. The availability of serotonin is contingent upon the conversion of tryptophan to 5-HTP. Since stressed people are typically lacking in serotonin, this may contribute to overeating. The addition of 5-HTP to the nutritional supplement serves as a precursor to serotonin. Coupled with the alpha lactalbumin-enriched whey, both should ensure that adequate serotonin is being produced. Generally, serotonin is produced within brain membranes by a process involving the interaction of the amino acid L-tryptophan with the enzyme trypophan hydroxylase. More particularly, two separate enzymatic steps are necessary for the synthesis of serotonin (5-HT) from its natural precursor tryptophan. The first step involves the conversion of tryptophan into 5-hydroxytryptophan (5-HTP) via interaction with the enzyme tryptophan hydroxylase. The second step involves the decarboxylation of 5-HTP into 5-HT via aromatic amino acid decarboxylase. The biosynthesis of 5-HT in the brain proceeds from the uptake of dietary tryptophan by the neuron, followed by its conversion to 5-hydroxytryptophan by an enzyme called tryptophan hydroxlyase. 5-HTP is decarboxylated to 5-HT by an enzyme called L-aromatic amino acid decarboxylase (AADC). When administered to animals or humans, 5-HTP is rapidly decarboxylated by an enzyme called L-amino acid decarboxylase also commonly called peripheral decarboxylase. Carbidopa is an inhibitor of L-aromatic amino acid decarboxylase. Carbidopa does not enter the brain, and thus administration of carbidopa selectively blocks the conversion of 5-HTP to 5-HT in the periphery, but not the brain. 5-HTP can be derived from Griffonia simplicifolia and made into a 95% pure standardized extract. Although 5-HTP is preferred, tryphtophan can be used.

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