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Dr. Bob is Robert Hsiung, MD,
[email protected]Shown: posts 1 to 7 of 7. This is the beginning of the thread.
Posted by iforgotmypassword on April 26, 2009, at 3:02:43
i know MAO-B apparently has the effect of metabolizing dopamine to some extent. in whichever way it does this, wherever in the brain, and to what extent, does this have a use? is there anything else that MAO does that has a use?
it may be that MAO-B inhibition may be unlikely to hurt people, it may be the basis of the one benefit of smoking. (referring to the research implying that it seems to delay idiopathic parkinsonian neurodegeneration.) smoking however, i don't believe wipes out MAO-B, so even if MAO-B inhibition was one of the safe effects of tobacco smoking, it may not indicate that total MAO-B inhibition over long periods in healthy individuals is without risk, if there is some use for this enzyme...
or, does MAO-B exist almost as if by accident, as an unavoidable product of MAO-A production?
Posted by SLS on April 26, 2009, at 5:49:56
In reply to purpose of MAO-B, posted by iforgotmypassword on April 26, 2009, at 3:02:43
> i know MAO-B apparently has the effect of metabolizing dopamine to some extent. in whichever way it does this, wherever in the brain, and to what extent, does this have a use? is there anything else that MAO does that has a use?
>
> it may be that MAO-B inhibition may be unlikely to hurt people, it may be the basis of the one benefit of smoking. (referring to the research implying that it seems to delay idiopathic parkinsonian neurodegeneration.) smoking however, i don't believe wipes out MAO-B, so even if MAO-B inhibition was one of the safe effects of tobacco smoking, it may not indicate that total MAO-B inhibition over long periods in healthy individuals is without risk, if there is some use for this enzyme...
>
> or, does MAO-B exist almost as if by accident, as an unavoidable product of MAO-A production?
As usual, you ask great questions that I cannot answer. I don't know the evolutionary history of the two isoenzymes, so it is difficult to guess which one acted as the primary enzyme of deamination. I know lobsters use serotonin, so they must have some MAO-A to regulate their metabolism.I believe that it is MAO-A that is the more relevant pharmacological target in the treatment of depression and anxiety disorders. It is interesting to note that the same person who does not respond robustly to the selegiline oral preparation does respond so when using the patch delivery system. Even at the lowest dosage, the patch system delivers enough selegiline for it to lose its selectivity for MAO-B and is thus inhibiting MAO-A as well. MAO-A does deaminate dopamine as well as norepinephrine and serotonin. We must take regional distribution of the two enzymes into account to really understand their function or emergence evolutionarily.
You should research at what point in the evolutionary development of the brain did the different isoenzymes emerge. Even looking at the more primative structures of the brain for enzyme distribution would be interesting.
- Scott
Posted by desolationrower on April 27, 2009, at 0:10:33
In reply to Re: purpose of MAO-B » iforgotmypassword, posted by SLS on April 26, 2009, at 5:49:56
well, MAOIs create abnormal brain states. mao regulates monoamines. thats one this it does
also mao is the natural ligand for the imadolazine-2 receptor
also, many things are only useful developmentally, they just kind of hang around afterward. lack of mao messes up developing brains.
-d/r
Posted by Alexanderfromdenmark on April 27, 2009, at 9:50:16
In reply to Re: purpose of MAO-B, posted by desolationrower on April 27, 2009, at 0:10:33
> well, MAOIs create abnormal brain states. mao regulates monoamines. thats one this it does
>
> also mao is the natural ligand for the imadolazine-2 receptor
>
> also, many things are only useful developmentally, they just kind of hang around afterward. lack of mao messes up developing brains.
>
> -d/rHow old do you reckon one should be before one is allowed to try an MAOI?
Posted by desolationrower on April 27, 2009, at 14:38:43
In reply to Re: purpose of MAO-B, posted by Alexanderfromdenmark on April 27, 2009, at 9:50:16
24 to be safe, i guess. although most of the animal research is more in the foetus/just born stage i think
-d/r
Posted by Alexanderfromdenmark on April 27, 2009, at 15:06:18
In reply to Re: purpose of MAO-B, posted by desolationrower on April 27, 2009, at 14:38:43
> 24 to be safe, i guess. although most of the animal research is more in the foetus/just born stage i think
>
> -d/rI was thinking about trying an MAOI next if I'm gonna try anymore AD's. Going 22 soon. But then again, I don't think SSRI's are any safer in young people anyway.
Posted by Chairman_MAO on May 13, 2009, at 23:11:19
In reply to Re: purpose of MAO-B » iforgotmypassword, posted by SLS on April 26, 2009, at 5:49:56
MAO-B also deaminates various trace amines, such
as phenethylamine.
This is the end of the thread.
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