Tyramine is generally degraded in the body by an enzyme called MAO (monoamine oxidase) [1].

Absorption, Distribution and Excretion
96% OF (14)C WAS EXCRETED IN 24-HR URINE OF RATS GIVEN IP DOSE OF...(14)C TYRAMINE. 67% WAS EXCRETED IN 3 HR, BUT THIS AMT WAS MARKEDLY REDUCED IF RATS WERE PRETREATED WITH MONOAMINE OXIDASE INHIBITOR. /HUMANS/...EXCRETED 58% OF (14)C IN 24-HR URINE FOLLOWING IV DOSE...
WHEN TYRAMINE...WAS INJECTED INTO RATS, MAJOR URINARY METABOLITE WAS FREE P-HYDROXYPHENYLACETIC ACID...(77% OF THAT PROPORTION OF DOSE EXCRETED IN URINE)...
.../TYRAMINE IS/ POORLY ABSORBED FROM BOWEL, BUT.../IS/ READILY ABSORBED FROM SC INJECTION. .../IT/ MAY BE ABSORBED TO A GREATER OR LESS EXTENT FROM NASAL MUCOSA.
(14)C-LABELED TYRAMINE BOUND TO PLASMA PROTEINS OF RABBITS IN DOSE- & TIME OF INCUBATION-RELATED MANNER. MAX BINDING CAPACITY EST AS 70.2 UG/G. AFFINITY FOR PLASMA PROTEINS MUCH LOWER THAN THAT OF NORADRENALINE.

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Metabolism / Metabolites
THERE HAVE BEEN SEVERAL...METABOLIC STUDIES OF TYRAMINE IN MAMMALS, & TRACERS HAVE BEEN USED. ...SMALL AMT OF P-HYDROXYMANDELIC ACID, VANILMANDELIC ACID, & HOMOVANILLIC ACID /HAVE BEEN INDENTIFIED/.
WHEN TYRAMINE...WAS INJECTED INTO RATS, MAJOR URINARY METABOLITE WAS FREE P-HYDROXYPHENYLACETIC ACID...
...TYRAMINE...PRESENT IN CHEESE AND IN YEAST EXTRACT...IS NORMALLY DETOXICATED BY MONOAMINE OXIDASE, PRESENT IN INTESTINE AND LIVER, TO YIELD PARA-HYDROXYPHENYLETHANOL, PARA-HYDROXYPHENYLACETIC ACID AND ITS GLYCINE CONJUGATE, PARA-HYDROXYPHENACETURIC ACID, AND...N-ACETYLTYRAMINE.
WHEN HUMAN/S/...TREATED WITH (14)C-TYRAMINE.../URINARY METABOLITE/ P-HYDROXYPHENYLACETALDEHYDE...CONTRIBUTED LESS THAN 0.5%.
For more Metabolism/Metabolites (Complete) data for TYRAMINE (6 total), please visit the HSDB record page.
Tyramine has known human metabolites that include Tyramine glucuronide and Dopamine.
Paraoxonase (PON1) is a key enzyme in the metabolism of organophosphates. PON1 can inactivate some organophosphates through hydrolysis. PON1 hydrolyzes the active metabolites in several organophosphates insecticides as well as, nerve agents such as soman, sarin, and VX. The presence of PON1 polymorphisms causes there to be different enzyme levels and catalytic efficiency of this esterase, which in turn suggests that different individuals may be more susceptible to the toxic effect of OP exposure.

Toxicity Summary
Tyramine is a cholinesterase or acetylcholinesterase (AChE) inhibitor. A cholinesterase inhibitor (or 'anticholinesterase') suppresses the action of acetylcholinesterase. Because of its essential function, chemicals that interfere with the action of acetylcholinesterase are potent neurotoxins, causing excessive salivation and eye-watering in low doses, followed by muscle spasms and ultimately death. Nerve gases and many substances used in insecticides have been shown to act by binding a serine in the active site of acetylcholine esterase, inhibiting the enzyme completely. Acetylcholine esterase breaks down the neurotransmitter acetylcholine, which is released at nerve and muscle junctions, in order to allow the muscle or organ to relax. The result of acetylcholine esterase inhibition is that acetylcholine builds up and continues to act so that any nerve impulses are continually transmitted and muscle contractions do not stop. Among the most common acetylcholinesterase inhibitors are phosphorus-based compounds, which are designed to bind to the active site of the enzyme. The structural requirements are a phosphorus atom bearing two lipophilic groups, a leaving group (such as a halide or thiocyanate), and a terminal oxygen.

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Interactions
ANTIBACTERIAL ACTION OF FURAZOLIDONE IS ACCOMPANIED BY PROGRESSIVE & GENERALIZED INHIBITION OF MONOAMINE OXIDASE... TYRAMINE HAS...BEEN REPORTED TO INTERACT WITH FURAZOLIDONE...
PHENYLPROPANOLAMINE & OTHER INDIRECT-ACTING SYMPATHOMIMETIC AMINES (EG, TYRAMINE) PRODUCE HYPERTENSIVE CRISIS & RELATED SYMPTOMS IN SOME INDIVIDUALS CURRENTLY RECEIVING OR PREVIOUSLY BEING TREATED WITH TRANYLCYPROMINE OR OTHER MONOAMINE OXIDASE INHIBITORS /SUCH AS ISOCARBOXAZID, PARGYLINE & PHENELZINE/. ...MAY BE FATAL.
ALTHOUGH SELECTIVE MONOAMINE OXIDASE INHIBITOR (-)-DEPRENYL SUBSTANTIALLY INHIBITS TYRAMINE (I)-OXIDIZING ABILITY IN PIG, IV TYRAMINE CHALLENGE AFTER PRETREATMENT WITH THIS DRUG FAILED TO PRODUCE PRESSOR RESPONSE ("CHEESE EFFECT") ASSOC WITH OTHER IRREVERSIBLE MAO INHIBITORS.
PRETREATMENT OF THYROIDECTOMIZED RATS WITH T3 & RESERPINE ABOLISHED TYRAMINE INDUCED HYPOTENSIVE ACTION. PRETREATMENT WITH PHENOXYBENZAMINE INHIBITED ACTION IN INTACT RAT AS WELL, WHEREAS CYPROHEPTADINE INCR ACTION IN THYROIDECTOMIZED RAT BUT NOT IN INTACT RATS
For more Interactions (Complete) data for TYRAMINE (11 total), please visit the HSDB record page.

[1]. The Monoamine Oxidase Inhibitor-Tyramine Interaction. J Clin Pharmacol. 1989 Jun;29(6):529-32.

Tyramine is a primary amino compound obtained by formal decarboxylation of the amino acid tyrosine. It has a role as an EC 3.1.1.8 (cholinesterase) inhibitor, a human metabolite, an Escherichia coli metabolite, a mouse metabolite and a neurotransmitter. It is a monoamine molecular messenger, a primary amino compound and a member of tyramines. It is a conjugate base of a tyraminium.
Tyramine (4-hydroxyphenethylamine; para-tyramine, mydrial or uteramin) is a naturally occurring monoamine compound and trace amine derived from the amino acid tyrosine. Tyramine acts by inducing the release of catecholamine. An important characteristic of this product is its impediment to cross the blood-brain barrier which restrains its side effects to only nonpsychoactive peripheral sympathomimetic effects. There have been reports of hypertensive crisis in patients ingesting tyramine-rich diet in conjunction with monoamine oxidase inhibitors (MAOIs).
Tyramine is a metabolite found in or produced by Escherichia coli (strain K12, MG1655).
Tyramine has been reported in Magnolia officinalis, Senegalia berlandieri, and other organisms with data available.
Tyramine is a monoamine compound derived from the amino acid tyrosine. Tyramine is metabolized by the enzyme monoamine oxidase. In foods, it is often produced by the decarboxylation of tyrosine during fermentation or decay. Foods containing considerable amounts of tyramine include fish, chocolate, alcoholic beverages, cheese, soy sauce, sauerkraut, and processed meat. A large dietary intake of tyramine can cause an increase in systolic blood pressure of 30 mmHg or more. Tyramine acts as a neurotransmitter via a G protein-coupled receptor with high affinity for tyramine called TA1. The TA1 receptor is found in the brain as well as peripheral tissues including the kidney. An indirect sympathomimetic, Tyramine can also serve as a substrate for adrenergic uptake systems and monoamine oxidase so it prolongs the actions of adrenergic transmitters. It also provokes transmitter release from adrenergic terminals.
Tyramine is a metabolite found in or produced by Saccharomyces cerevisiae.
An indirect sympathomimetic that occurs naturally in cheese and other foods. Tyramine does not directly activate adrenergic receptors, but it can serve as a substrate for adrenergic uptake systems and MONOAMINE OXIDASE to prolong the actions of adrenergic transmitters. It also provokes transmitter release from adrenergic terminals and may be a neurotransmitter in some invertebrate nervous systems.
See also: Tyramine hydrochloride (is active moiety of); Cytisus scoparius flowering top (part of); Selenicereus grandiflorus stem (part of).

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Mechanism of Action
... Findings indicate that tyramine acts presynaptically to cause a release of endogenous norepinephrine from the nerve, which in turn acts on postjunctional receptors.

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Therapeutic Uses
Adrenergic alpha-Agonists; Adrenergic Agents; Adrenergic Uptake Inhibitors; Sympathomimetics
/TYRAMINE WAS/...FORMERLY /USED/ AS HYPOTENSIVE, OXYTOCIC.
...HAS BEEN USED @ 2% CONCN IN MYDRIATIC EYEDROPS. THIS HAS BEEN SAID TO REDUCE INTRAOCULAR PRESSURE...IN SOME PATIENTS WITH OPEN-ANGLE GLAUCOMA.

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Drug Warnings
...PREPARATIONS HAVE NOT CAUSED DEATH, BUT...THERAPEUTIC USE PRODUCES SIDE ACTIONS WHICH ARE OFTEN UNPLEASANT. /TYRAMINE HYDROCHLORIDE/
NO ADVERSE EFFECTS ON THE EYE APPEAR TO HAVE BEEN REPORTED, BUT PRESUMABLY ANGLE-CLOSURE GLAUCOMA COULD BE INDUCED BY MYDRIASIS IN EYES HAVING PATHOLOGICALLY NARROW ANGLES & SHALLOW ANTERIOR CHAMBERS.
AVG MEAL OF NATURAL OR AGED CHEESES CONTAINS ENOUGH TYRAMINE TO PROVOKE MARKED RISE IN BLOOD PRESSURE & OTHER CARDIOVASCULAR CHANGES. ... OTHER FOODS IMPLICATED...SNAILS...YEAST, LARGE QUANTITIES OF COFFEE, CITRUS FRUITS, CANNED FIGS, BROAD BEANS... PT BEING TREATED WITH MAO INHIBITOR...GIVEN LIST OF FOODS TO BE AVOIDED...
Consumption of foods containing more than 10 g of tyramine (eg, aged cheeses, yeast products) together with monoamine oxidase (MAO) inhibitor drugs may lead to serious hypertensive reactions.

C8H11NO

137.17904

137.084

51-67-2

51-67-2;60-19-5 (chloride);

5610

CRYSTALS FROM BENZENE OR ALCOHOL
PLATES OR NEEDLES FROM BENZENE, NEEDLES FROM WATER

1.1±0.1 g/cm3

275.1±23.0 °C at 760 mmHg

160-162 °C(lit.)

141.3±13.3 °C

0.0±0.6 mmHg at 25°C

1.600

1.38

2

2

2

10

87.3

0

C1=C(C=CC(=C1)O)CCN

DZGWFCGJZKJUFP-UHFFFAOYSA-N

InChI=1S/C8H11NO/c9-6-5-7-1-3-8(10)4-2-7/h1-4,10H,5-6,9H2

4-(2-aminoethyl)phenol

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: This product requires protection from light (avoid light exposure) during transportation and storage.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~33.33 mg/mL (~242.97 mM)
H2O : ~5.26 mg/mL (~38.34 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (18.22 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: 2.5 mg/mL (18.22 mM) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), suspension solution; with ultrasonication.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (18.22 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: 4 mg/mL (29.16 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication (<60°C).

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 (Please use freshly prepared in vivo formulations for optimal results.)