tyramine and hypertension

[dark_angel177]

Concerning MAOIs and side effects with the consumption of foods containing tyramine (the cheese reaction)

Granted that tyramine is an intermediate product of the coverstion of tryrosine into epinephrine, how is it that when additional tyramine is introduced and is unable to be inactivated (because monoamine oxidation is inhibited) an excess of epinephrine is produced? Through what process does tyramine convert into epinephrine?

If MAOIs are used to decrease the concentration of MAO neurotransmitters why does the increase in the production of epinephrine through this act as the antidepressant mechanism and not cause the side effects to occur unless one ingests foods high in tyramine?

All apologies for the confusion and any insight would be greatly apprecaited.

 

[BilZ0r]

Tyramine acts like weak amphetamine. It has a low affinity for transport through the noradrenaline transporter, which then causes noradrenaline release. So when tyramine oxidation is inhibited, it builds up, and acts like amphetamine.