Getting rid of glutamate to prevent brain injury

Vivian Teichberg has hit upon a novel way to prevent neuronal death following an insult to the brain. Glutamate is an excitatory amino acid, which is necessary for normal brain function. However, it becomes excito-toxic when released in large amounts, which is exactly what happens during an injury. How to stop this? Well, you could interfere with the actions of glutamate; or you can remove excess glutamate from the brain via the bloodstream.

"Normally the brain recognizes the fact that the glutamate is extremely toxic and has an inherent defense mechanism which pumps it back into the brain cells," says Teichberg. However, with trauma or disease, the brain's normal mechanisms don't function properly. They need a helping hand. Teichberg's idea was to move the excess glutamate from the brain into the blood, which would then carry it safely away and prevent its destructive effects. [snip] There is an enzyme present in blood, known as GOT, which is able to break down glutamate in the presence of a chemical called oxaloacetate (O). Teichberg figured that by injecting large amounts of O into the bloodstream, this would "drive" more glutamate from the brain into the bloodstream. "After a head injury, you give one injection of O for a short, intense time of thirty minutes, and this drains excess glutamate from the brain into the blood and protects the brain."

Sounds good. Of course, one of the problems with trying to affect glutamate levels in the brain is that brain function is so dependent on glutamate (I think the number of glutamatergic neurons in the brain approaches 50%, but don't quote me on that) that decreasing levels all around runs the danger of placing the patient into a coma. However, perhaps this method, though systemic, would only be functional near the injury site (due to the high concentration) and not really affect non-injury sites.