Posted by SLS on June 1, 2002, at 18:51:16
In reply to glutamine, posted by Shelley on June 1, 2002, at 11:50:35
> Does anyone know if the amino acid glutamine can have toxic effects if taken as a supplement? I find that it has the effect of an anti-convulsant or mood stabilizer. But it is somehow related to glutamate, which is considered a neurotoxin, and apparently can elevate brain levels of the latter.
> Any information on this would be appreciated.
> TIA,
> Shelley.
Hi Shelley.I'm curious. What are your reasons for wanting to take glutamine?
I can't answer your question definitively, but I decided to do a little snooping.
I did a quick search on Google, and there are some websites that caution against using glutamine supplements for fear of neurotoxicity. However, I'm not sure that there is any basis for such concerns. I wouldn't think so. None of the websites I visited demonstrated when or detailed how such a thing occurs. They pretty much just guessed or theorized. They provided no facts or citations to support their contentions. My searches on Medline provided none.
Glutamine and glutamate are both amino acids that the body manufactures on its own. The body manipulates glutamine and glutamate through several metabolic pathways. Each can be converted into the other, depending on which enzymes are involved.
glutamate -> glutamine
glutamine -> glutamateGlutamate is not a neurotoxin.
Glutamate is an important neurotransmitter. In fact, it is the most abundant of excitatory neurotransmitters (GABA being the most abundant of the inhibitory neurotransmitters). Like many other things, too much of a good thing can be bad. Normally, glutamate stimulates and signals a neuron to allow extracellular Ca2+ calcium ions to pass through the cell membrane into the cell. This one of the events that facilitates healthy neurons to communicate to each other. However, when glutamate is present in excess, neurons are overstimulated and allow abnormally high numbers of Ca2+ calcium ions to rush into the neuron. It is this excess of calcium within the cell that becomes toxic. This type of toxicity is called excitotoxicity, and can lead to the damage or death of nerves.
I'm not sure of all the ways glutamate levels come to be abnormally high, but neurons damaged by trauma or stroke will leak glutamate and overstimulate neighboring neurons. I'm guessing that too much chronic psychosocial stress or excessive cortisol production in response to stress might be involved. I don't know for sure. However, I don't think the levels of glutamate that neurons are exposed to are affected by how much glutamine or glutamate one ingests. Maybe someone else knows for sure. I think it is the active machinery of the cells that determines how much glutamate is processed and released into the neural environment.
I hope this helps.
- Scott
poster:SLS
thread:108301
URL: http://www.dr-bob.org/babble/20020525/msgs/108338.html