5-Hydroxytryptophan: Difference between revisions

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==Pharmacology==

The psychoactive action of 5-HTP is derived from its increase in production of serotonin in central nervous system tissue. 5-HTP is decarboxylated to serotonin (5-hydroxytryptamine or 5-HT) by the enzyme aromatic-L-amino-acid decarboxylase with the help of vitamin B6.<ref>https://www.ncbi.nlm.nih.gov/pubmed/6983619 | Effect of pyridoxal phosphate deficiency on aromatic L-amino acid decarboxylase activity with L-DOPA and L-5-hydroxytryptophan as substrates in rats.</ref> This reaction occurs both in nervous tissue and in the liver.<ref>https://www.ncbi.nlm.nih.gov/pubmed/6974228 | Characteristics of dihydroxyphenylalanine/5-hydroxytryptophan decarboxylase activity in brain and liver of cat.</ref> 5-HTP crosses the blood–brain barrier,<ref>https://www.ncbi.nlm.nih.gov/pubmed/18445233 | Augmented brain 5-HT crosses the blood-brain barrier through the 5-HT transporter in rat.</ref> ~~while~~ 5-HT ~~does not.~~

The psychoactive action of 5-HTP is derived from its increase in production of [[serotonin]] in central nervous system tissue. 5-HTP is decarboxylated to serotonin (5-hydroxytryptamine or 5-HT) by the enzyme 'aromatic-L-amino-acid decarboxylase', with the help of vitamin B6.<ref>https://www.ncbi.nlm.nih.gov/pubmed/6983619 | Effect of pyridoxal phosphate deficiency on aromatic L-amino acid decarboxylase activity with L-DOPA and L-5-hydroxytryptophan as substrates in rats.</ref> This reaction occurs both in nervous tissue and in the liver.<ref>https://www.ncbi.nlm.nih.gov/pubmed/6974228 | Characteristics of dihydroxyphenylalanine/5-hydroxytryptophan decarboxylase activity in brain and liver of cat.</ref> 5-HTP crosses the blood–brain barrier, while 5-HT (serotonin) does not.<ref>https://www.ncbi.nlm.nih.gov/pubmed/18445233 | Augmented brain 5-HT crosses the blood-brain barrier through the 5-HT transporter in rat.</ref>

Excess 5-HTP, especially when administered with vitamin B6, is thought to be metabolized and excreted.<ref>Biochemical properties and kinetic parameters of dihydroxyphenylalanine--5-hydroxytryptophan decarboxylase in brain, liver, and adrenals of cat | doi=10.1139/o79-126}}</ref><ref>title=On the tryptophan-serotonin metabolism in manic-depressive disorders. Changes in plasma 5-HT and 5-HIAA levels and urinary 5-HIAA excretion following oral loading of L-5HTP in patients with depression | |pmid=1088369 </ref>

5-HTP is [[decarboxylation|decarboxylated]] to [[serotonin]] (5-hydroxytryptamine or 5-HT) by [[aromatic-L-amino-acid decarboxylase]] with the help of [[vitamin B6|vitamin B6]].<ref>{{Effect of pyridoxal phosphate deficiency on aromatic L-amino acid decarboxylase activity with L-DOPA and L-5-hydroxytryptophan as substrates in rats | doi=10.1254/jjp.32.803}}</ref> This reaction occurs both in nervous tissue and in the liver.<ref>Characteristics of dihydroxyphenylalanine/5-hydroxytryptophan decarboxylase activity in brain and liver of cat | doi = 10.1111/j.1471-4159.1982.tb12555.x</ref> 5-HTP crosses the [[blood–brain barrier]],<ref>Augmented brain 5-HT crosses the blood-brain barrier through the 5-HT transporter in rat | doi=10.1111/j.1460-9568.2008.06201.x</ref> while 5-HT does not. Excess 5-HTP, especially when administered with vitamin B6, is thought to be metabolized and excreted.<ref>Biochemical properties and kinetic parameters of dihydroxyphenylalanine--5-hydroxytryptophan decarboxylase in brain, liver, and adrenals of cat | doi=10.1139/o79-126}}</ref><ref>title=On the tryptophan-serotonin metabolism in manic-depressive disorders. Changes in plasma 5-HT and 5-HIAA levels and urinary 5-HIAA excretion following oral loading of L-5HTP in patients with depression | |pmid=1088369 </ref>

==Subjective effects==

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 ==Pharmacology==
-The psychoactive action of 5-HTP is derived from its increase in production of serotonin in central nervous system tissue. 5-HTP is decarboxylated to serotonin (5-hydroxytryptamine or 5-HT) by the enzyme aromatic-L-amino-acid decarboxylase with the help of vitamin B6.<ref>https://www.ncbi.nlm.nih.gov/pubmed/6983619 | Effect of pyridoxal phosphate deficiency on aromatic L-amino acid decarboxylase activity with L-DOPA and L-5-hydroxytryptophan as substrates in rats.</ref> This reaction occurs both in nervous tissue and in the liver.<ref>https://www.ncbi.nlm.nih.gov/pubmed/6974228 | Characteristics of dihydroxyphenylalanine/5-hydroxytryptophan decarboxylase activity in brain and liver of cat.</ref> 5-HTP crosses the blood–brain barrier,<ref>https://www.ncbi.nlm.nih.gov/pubmed/18445233 | Augmented brain 5-HT crosses the blood-brain barrier through the 5-HT transporter in rat.</ref> while 5-HT does not.
+The psychoactive action of 5-HTP is derived from its increase in production of [[serotonin]] in central nervous system tissue. 5-HTP is decarboxylated to serotonin (5-hydroxytryptamine or 5-HT) by the enzyme 'aromatic-L-amino-acid decarboxylase', with the help of vitamin B<sub>6</sub>.<ref>https://www.ncbi.nlm.nih.gov/pubmed/6983619 | Effect of pyridoxal phosphate deficiency on aromatic L-amino acid decarboxylase activity with L-DOPA and L-5-hydroxytryptophan as substrates in rats.</ref> This reaction occurs both in nervous tissue and in the liver.<ref>https://www.ncbi.nlm.nih.gov/pubmed/6974228 | Characteristics of dihydroxyphenylalanine/5-hydroxytryptophan decarboxylase activity in brain and liver of cat.</ref> 5-HTP crosses the blood–brain barrier, while 5-HT (serotonin) does not.<ref>https://www.ncbi.nlm.nih.gov/pubmed/18445233 | Augmented brain 5-HT crosses the blood-brain barrier through the 5-HT transporter in rat.</ref>
+Excess 5-HTP, especially when administered with vitamin B<sub>6</sub>, is thought to be metabolized and excreted.<ref>Biochemical properties and kinetic parameters of dihydroxyphenylalanine--5-hydroxytryptophan decarboxylase in brain, liver, and adrenals of cat | doi=10.1139/o79-126}}</ref><ref>title=On the tryptophan-serotonin metabolism in manic-depressive disorders. Changes in plasma 5-HT and 5-HIAA levels and urinary 5-HIAA excretion following oral loading of L-5HTP in patients with depression | |pmid=1088369 </ref>
--HTP is [[decarboxylation|decarboxylated]] to [[serotonin]] (5-hydroxytryptamine or 5-HT) by [[aromatic-L-amino-acid decarboxylase]] with the help of [[vitamin B6|vitamin B<sub>6</sub>]].<ref>{{Effect of pyridoxal phosphate deficiency on aromatic L-amino acid decarboxylase activity with L-DOPA and L-5-hydroxytryptophan as substrates in rats | doi=10.1254/jjp.32.803}}</ref>  This reaction occurs both in nervous tissue and in the liver.<ref>Characteristics of dihydroxyphenylalanine/5-hydroxytryptophan decarboxylase activity in brain and liver of cat | doi = 10.1111/j.1471-4159.1982.tb12555.x</ref>  5-HTP crosses the [[blood–brain barrier]],<ref>Augmented brain 5-HT crosses the blood-brain barrier through the 5-HT transporter in rat | doi=10.1111/j.1460-9568.2008.06201.x</ref> while 5-HT does not.  Excess 5-HTP, especially when administered with vitamin B<sub>6</sub>, is thought to be metabolized and excreted.<ref>Biochemical properties and kinetic parameters of dihydroxyphenylalanine--5-hydroxytryptophan decarboxylase in brain, liver, and adrenals of cat | doi=10.1139/o79-126}}</ref><ref>title=On the tryptophan-serotonin metabolism in manic-depressive disorders. Changes in plasma 5-HT and 5-HIAA levels and urinary 5-HIAA excretion following oral loading of L-5HTP in patients with depression | |pmid=1088369 </ref>
 ==Subjective effects==
 {{EffectStub}}