Glutamic acid in nervous tissue and changes of the taurine content: its implication in the treatment of epilepsy.

In order to account for interdependent changes in the steady state cerebral levels of glutamic acid, taurine and glutamine, two compartments are considered which are connected by an adjustable flow valve. The first compartment may be equated with neuronal structures and confines most of the steady state content of glutamic acid. The second compartment represents glia and contains most cerebral glutamine; taurine is sequestered by both anatomic compartments. The adjustable valve symbolises a combination of rate limited release, transport, and enzymic mechanisms responsible for connecting the glutamate containing structures with those sequestering glutamine. These compartments only represent a portion of the total intracerebral metabolism of glutamic acid (see 19).