Tyramine

In tyrosine.^[1] Tyramine can cause the release of stored monoamines, such as dopamine, norepinephrine, epinephrine.

Occurrence

Tyramine occurs widely in plants and animals and is metabolized by the yeast, red wine, and an array of Cacti.

Metabolism

In humans, if monoamine metabolism is compromised by the use of cheese syndrome," even though other foods can cause the same problem.

Effects

A large dietary intake of tyramine (or a dietary intake of tyramine while taking MAO inhibitors) can cause the 'tyramine pressor response,' which is defined as an increase in systolic blood pressure of 30 mmHg or more. The displacement of norepinephrine(noradrenaline) from neuronal storage vesicles by acute tyramine ingestion is thought to cause the vasoconstriction and increased heart rate and blood pressure of the pressor response.

However, if one has had repeated exposure to tyramine, there is a decreased pressor response; Tyramine is degraded to synapse, and octopamine does not activate alpha or beta adrenergic receptors.

The possibility that tyramine acts directly as a neurotransmitter was revealed by the discovery of 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. The existence of a receptor with high affinity for tyramine supports the hypothesis that tyramine may also act directly to affect blood pressure regulation.

Migraine

Dietary tyramine intake has also been associated with migraine in select populations, leading many sufferers to restrict foods high in tyramine.^[2] Reports on the tyramine-migraine link have been both affirmed and denied. A recent review article found that all past studies affirming a migraine-tyramine connection were scientifically inconclusive, and noted several studies showing no connection. Two studies validated as scientifically sound reported no connection in the population evaluated.

References

See also

• List of foods containing tyramine