Posted by dennison on January 31, 2001, at 21:37:27
In reply to Re: High doses of Parnate-SLS?, posted by dennison on January 31, 2001, at 12:48:29
Hi scott--regarding your questions concerning tranylcypromine: Octopamine is the main false neuro-transmitter that is formed inside the cell as the main function of maoi "mono-amine-oxidase" which of course is blocked by parnate is to maintain metabolic purity of neurotransmitter production. When it is blocked many so called false neurotransmitters built in amounts that normally would be metabolized by mao enzmye. Octopamine is beta-hydroxylated tyramine. Tyramine oddly enough although to be strictly avoided dietarily in any significant amounts still is produced from dietary tyrosine. This tyramine is taken up into the cell and serves as a substrate for beta-hydroxylation forming octopamine in high amounts. This conc. of octopamine indeed displaces intragranular norepinephine. Then when the normal norepinephrine is to be released into the synaptic cleft"synapse" octopamine is released instead of normal norepinephrine. Since octopamine is nearly totally ineffective (1%of the potency of norepinephrine)at stimulating post-synaptic receptors functionally the peripheral autonomic nervous system effect is totally abolished. Hence the low blood pressure---reduced cardiac output from venous pooling etc. As in regards to your reference to pea as a possible metabolite of tranylcypromine itself, the normal
breakdown product is cinnamon aldehyde. Now of course parnate itself causes huge increases of (PEA) by it's direct blockade of mono-amine oxidase B which is the main enzyme metabolizing phenylethylamine(PEA). Pea is a trace amine normally just as octopamine is normally a trace amine it is well known that maoi's cause hugh increases in trace amines (another is tryptamine). P.S. --the reason that phenylethylamine type byproducts of parnate itself are not seen is because parnate has been shown not to undergo cyclopropyl ring opening which would be necessary to form the phenylethylamine backbone,instead cinnamon aldehyde is the breakdown product of parnate.
poster:dennison
thread:46965
URL: http://www.dr-bob.org/babble/20010131/msgs/53065.html