Posted by Larry Hoover on June 18, 2004, at 16:21:20
In reply to Re: GABA » Larry Hoover, posted by Questionmark on June 17, 2004, at 14:47:05
> > Someone recently raised an interesting conjecture....if GABA is converted to GHB by a certain enzyme (succinic aldehyde reductase or something like that...
Okay, here's the post that I'm recalling....
http://www.dr-bob.org/babble/alter/20040418/msgs/351881.html
> > More generally, I think the argument itself is somewhat moot. Arguing mechanisms to explain (or refute) actual experience is not going to tell us much. Empiricism (what people actually observe) is reality. If people feel less anxiety with oral GABA, then that sounds like a good thing to me. Geeks have been wrong before.
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> > Lar
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> i compLETEly agree (w/ your last paragraph). That's the trap that so many psychiatrists fall into and it ticks me off beyond words. i just wasn't sure how many people did feel something with GABA and how noticeable/potent any effects were.Apparently, people do feel the effect of oral GABA.
> i didn't know that GABA was a relatively small molecule. You're probably right then (about the "trickle-in effect").
> i think i also remember reading that GHB crosses the BBB via passive diffusion. But do you think that GABA is really converted into GHB by an endogenous enzyme (okay i think all enzymes are endogenous but i mean without taking anything with the GABA or anything)? That's great if that's true, considering all the positive things i've heard about GHB and anxiety & depression. How likely do you think it is that some [peripheral/ supplemental] GABA is converted to GHB in the body? And if you have any idea, what proportion of GABA (in supplement form, ingested) do you think IS converted to GHB?
Here's a representation of the different chemical pathways involved:
http://www.ceri.com/ghbalt.htmUnfortunately, the poster who raised the question of conversion of GABA to GHB had some factual errors. The oxidation product of GHB is succinic semialdehyde. The enzyme succinic semialdehyde reductase reduces succinic semialdehyde back to GHB. The interconversion of GABA and GHB involves quite a different enzyme altogether (one of the transaminases).
Enzymes are not "smart".....they don't only cause reactions to go in one direction. Although we think of GHB being aminated to form GABA, if the concentration of GABA is high enough, the enzyme will tend to deaminate GABA to GHB. Looking at the cycles, though, I doubt that is a common occurrence, even with oral GABA. But, I'm guessing.
> Finally, do you or anyone else have any good idea about how much GABA to take to notice significant (i.e., definitely noticeable) anxiolytic (anti-anxiety) effects?I do not know. I suspect there is individual variation on that, but I never did a good experiment to know my own threshold.
> Thanks so much for your help Larry, & anyone else who might reply.
You're welcome.
Lar
poster:Larry Hoover
thread:357170
URL: http://www.dr-bob.org/babble/alter/20040613/msgs/357903.html