5-羥色氨酸

5-hydroxytryptophan is a tryptophan derivative that is tryptophan substituted by a hydroxy group at position 5. It has a role as a human metabolite and a neurotransmitter.

5-Hydroxytryptophan, DL- is a racemic mixture of 5-hydroxytryptophan (5-HTP), a precursor to the neurotransmitter serotonin with anti-depressant, analgesic and appetite-suppressant activities. DL-5-HTP is decarboxylated to serotonin by aromatic-L-amino-acid decarboxylase, and results in increased serotonin levels within the brain. Mediated through serotonin receptors, elevated levels of serotonin causes increased serotonin neurotransmissions, hence leading to release of depression, pain and appetite.

5-Hydroxy-L-tryptophan is an aromatic amino acid naturally produced by the body from the essential amino acid l-tryptophan. 5-Hydroxy-L-tryptophan is the immediate precursor of the neurotransmitter serotonin. The conversion to serotonin is catalyzed by the enzyme aromatic l-amino acid decarboxylase (EC 4.1.1.28, AADC1 also known as dopa decarboxylase), an essential enzyme in the metabolism of the monoamine neurotransmitters. An accumulation of 5-Hydroxy-L-tryptophan in cerebrospinal fluid occurs in Aromatic l-amino acid decarboxylase deficiency (OMIM 608643), accompanied by an increased excretion in the urine of the patients, which are indicative of the disorder but not specific 5-Hydroxy-L-tryptophan is also increased in other disorders such as in Parkinson's patients with severe postural instability and gait disorders. Confirmation of the diagnosis AADC deficiency is then required by enzyme activity measurement or genetic analysis. The amount of endogenous 5-Hydroxy-L-tryptophan available for serotonin synthesis depends on the availability of tryptophan and on the activity of various enzymes, especially tryptophan hydroxylase (EC 1.14.16.4), indoleamine 2,3-dioxygenase (EC 1.13.11.52), and tryptophan 2,3-dioxygenase. (EC 1.13.11.11, TDO). 5-Hydroxy-L-tryptophan has been used clinically for over 30 years. In addition to depression, the therapeutic administration of 5-Hydroxy-L-tryptophan has been shown to be effective in treating a wide variety of conditions, including fibromyalgia, insomnia, binge eating associated with obesity, cerebellar ataxia, and chronic headaches. 5-Hydroxy-L-tryptophan easily crosses the blood-brain barrier and effectively increases central nervous system (CNS) synthesis of serotonin. Supplementation with 5-Hydroxy-L-tryptophan is hypothesized to normalize serotonin synthesis, which is putatively related to its antidepressant properties. (A3384, A3385, A3386).

The immediate precursor in the biosynthesis of SEROTONIN from tryptophan. It is used as an antiepileptic and antidepressant.

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