Item |
Information |
Drug Groups
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approved; nutraceutical |
Description
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A non-essential amino acid. In animals it is synthesized from phenylalanine. It is also the precursor of epinephrine; thyroid hormones; and melanin. [PubChem] |
Indication |
Tyrosine is claimed to act as an effective antidepressant, however results are mixed. Tyrosine has also been claimed to reduce stress and combat narcolepsy and chronic fatigue, however these claims have been refuted by some studies. |
Pharmacology |
Tyrosine is a nonessential amino acid synthesized in the body from phenylalanine. Tyrosine is critical for the production of the body's proteins, enzymes and muscle tissue. Tyrosine is a precursor to the neurotransmitters norepinephrine and dopamine. It can act as a mood elevator and an anti-depressant. It may improve memory and increase mental alertness. Tyrosine aids in the production of melanin and plays a critical role in the production of thyroxin (thyroid hormones). Tyrosine deficiencies are manifested by hypothyroidism, low blood pressure and low body temperature. Supplemental tyrosine has been used to reduce stress and combat narcolepsy and chronic fatigue. |
Toxicity |
L-Tyrosine has very low toxicity. There have been very few reports of toxicity. LD50 (oral, rat) > 5110 mg/kg. |
Affected Organisms |
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Humans and other mammals |
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Biotransformation |
In the liver, L-tyrosine is involved in a number of biochemical reactions, including protein synthesis and oxidative catabolic reactions. L-tyrosine that is not metabolized in the liver is distributed via the systemic circulation to the various tissues of the body. |
Absorption |
L-tyrosine is absorbed from the small intestine by a sodium-dependent active transport process. |
References |
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Hoffhines AJ, Damoc E, Bridges KG, Leary JA, Moore KL: Detection and purification of tyrosine-sulfated proteins using a novel anti-sulfotyrosine monoclonal antibody. J Biol Chem. 2006 Dec 8;281(49):37877-87. Epub 2006 Oct 17.
[Pubmed]
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Molnar GA, Wagner Z, Marko L, Ko Szegi T, Mohas M, Kocsis B, Matus Z, Wagner L, Tamasko M, Mazak I, Laczy B, Nagy J, Wittmann I: Urinary ortho-tyrosine excretion in diabetes mellitus and renal failure: evidence for hydroxyl radical production. Kidney Int. 2005 Nov;68(5):2281-7.
[Pubmed]
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Molnar GA, Nemes V, Biro Z, Ludany A, Wagner Z, Wittmann I: Accumulation of the hydroxyl free radical markers meta-, ortho-tyrosine and DOPA in cataractous lenses is accompanied by a lower protein and phenylalanine content of the water-soluble phase. Free Radic Res. 2005 Dec;39(12):1359-66.
[Pubmed]
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External Links |
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