Tyrosine, Tyramine &Co

[Guest guest]

Hi all,

By reading all posted mails on this subjet, I found it may be worthwhile to

post some more information, thus answering parts of those mails:

Tyrosine,dopamine and tyramine

L-tyrosine is one of the 20 amino acids which constitute our proteins.

L-tyrosine is also the precursor of the L-DOPA (principal componant of

Sinemet) and L-DOPA is further transformed in dopamine, with the aid of vit

B6. For Parkinsonism (and probably RLS), dopamine is useful into the brain

but is not able to penetrate into it. To aleviate this problem, Sinemet

contains L-DOPA (able to enter the brain) and also another chemical which

inhibits its transformation in dopamine before the molecule enter the brain.

Now, if you ingest supplementary L-tyrosine, 99% is metabolized by the so

called main pathway and gives you energy and important other metabolites,

like your beefsteak. Vitamin C is required for one of these transformation

steps. Among the 1% remaining, metabolized through the alternate pathway, a

part is transformed to tyramine most probably by the bacteria contained in

your gut. The remaining part from the L-tyrosine, which is " swimming " in

your blood is able to reach the neuronal cells where it is transformed to

L-DOPA and dopamine.

As 99% of the tyrosine is " lost " for our RLS-interest, you may realize why

tyrosine supplements have to be ingested in grams in order to have an

effect, contrarily to vitamin supplements.

Tyrosine from milk and other proteins is partially transformed by bacteria

into tyramine during fermentation, reason why cheese,wine, beer,

sausages,...all fermented products contain a lot of tyramine.

Now, when you ingest tyramine with cheese or coming from the intake of

tyrosine supplements, tyramine is absorbed by the walls of the gut and

reaches the blood stream where it is able to increase the blood pressure.

Normally, only tiny amounts of tyramine are able to cross the walls because

an enzyme from the gut destroy tyramin more rapidly. This enzyme is the MAO.

This explain why people taking anti-MAO have to pay attention not to eat too

much cheese,..., otherwise too much tyramine is able to reach the blood

stream.

Tyrosine and depression

Some depressions are typically called dopamine-dependent. In such cases, it

was shown that the intake of L-tyrosine (average 3 grams /day) was able to

reduce and control the depression. In my opinion, it is well-advised to try

L-tyrosine for a RLS-patient having depression, instead to prescribe a

tricyclic antidepressant which is known to be able to fire the RLS symptoms.

It would remain a lot more to write, but I think you are most probably bored

now, and I have to rest!

a good sleep wish you:

Bernard & Mireille, Switzerland