Posted by Chairman_MAO on May 8, 2005, at 18:56:54
In reply to Re: Mode of action unknown » Chairman_MAO, posted by Larry Hoover on May 8, 2005, at 12:57:24
> I believe MAO is a synaptic cleft enzyme, designed to "corral" any stray neurotransmitter that didn't: a) hit its designated receptor (post-synaptic); b) hit its designated auto-receptor (pre-synaptic); c) get vacuumed up by the reuptake pump (pre-synaptic). Inhibiting MAO would, presumably, slightly enhance all of the above. However, it shunts "escaped" neurotransmitters to other scavenger enzymes, e.g. COMT. Thus, the metabolites of the catecholamines must change proportion and concentration. Perhaps that is the mode of action, metabolite-mediated response elements.
>
> Lar
http://www.cnsforum.com/imagebank/item/Drug_MOAI_2/index.htmlNote how MAO-A is found intraneuronally as well. Thus MAOIs alter the amount of neurotransmitter available for release. One possible therapeutic mechanism I can postulate a priori is that certain people have disorders that perturb the storage of neurotransmitters inside neurons. MAOIs could allow proper amounts of the transmitter to accumulate. I don't know if this has ever been discussed in the literature or not--or if it even makes total sense, heh--just came to mind.
Contrarily, while MAO-A is found in synapses as well as intraneuronally in catacholaminergic neurons, MAO-B is primarily a glial enzyme and is also found in serotonergic neurons.
poster:Chairman_MAO
thread:494113
URL: http://www.dr-bob.org/babble/20050504/msgs/495321.html