Posted by Questionmark on November 4, 2008, at 0:42:01
In reply to Re: Reuptake/ihibition/enzyme degradation » Questionmark, posted by JadeKelly on November 3, 2008, at 14:52:48
One never needs to be sorry for having limited knowledge in a certain area as long as the person is aware or tries their best to be aware of their limited knowledge, as you have.
Yes, reuptake inhibition of a neurotransmitter, and inhibition of an enzyme that breaks down that neurotransmitter, should theoretically essentially both have the same end result of allowing more of that neurotransmitter to be available within a neuron or a synaptic space.
Practically speaking overall, however, it can often be quite a bit more complicated than that, depending on various factors.
But there are many possible reasons why, for example, MAOIs produce different effects than other ADs like SSRIs. There could be differences in MAO concentrations in different areas of the brain that do not correlate with differences in proportions of transporter (reuptake pump) sites. MAO inhibition can also result in a greater amount of elevated neurotransmitter levels than can reuptake inhibition, from what I understand-- especially or at least in regard to serotonin-- which could result in somewhat different effects. And it's also possible that MAOIs alter receptor adaptation in a different way or to a different extent-- or alters/affects some of the specific receptor subtypes in different proportions-- than SSRIs or other neurochemical reuptake inhibitors. But beyond all that, and as you noted in your other later post about selectivity vs sledge-hammer, MAOIs affect a *number* of different neurotransmitters, while SSRIs for instance primarily if not solely (for some) affect serotonin.
A number of people here including myself who have had success with an MAOI have wondered if some certain medication combination which directly increased transmission of the same main neurotransmitters that MAOIs do... could be just as or more effective as a single MAOI. But so far, for whatever the reasons, based on our little trials and anecdotes here it looks as if that generally just isn't the case.
There's just something special about those MAOIs, for many people.
> > Good point, practically speaking. However-- and sorry to be technical, but-- Nardil does not affect GABA *reuptake* at all as far as we know, it inhibits the enzyme (GABA-transaminase I believe) that degrades GABA, the end result probably essentially being the same thing as if it inhibited its reuptake-- namely, more synaptic GABA available. So, you're still right that one may not need as much if any benzo while on Nardil, potentially.
>
> 1st, sorry for my limited knowledge, its why I'm here. Are you saying that reuptake inhibition, and inhibition (or destruction) of enzymes that degrade, have essentially the same end result? If thats an absurd interpretation, sorry!
>
> If not, why then do MAOI's work so much better than say, SSRI's? (I know, not true for many but a lot, me for one. MAOI's only AD ever touched my depression). Just curious. Thanks!
>
> Jade
poster:Questionmark
thread:860399
URL: http://www.dr-bob.org/babble/20081027/msgs/860688.html