Figure 4.

The neuroprotective effect of oxaloacetate is due to the decrease in blood glutamate levels as a result of the activation of a blood-resident enzyme glutamate-oxaloacetate transaminase (GOT). The latter enzyme causes a reversible reaction in which glutamate reacts with oxaloacetate to transfer an amino group, transforming glutamate into α-ketoglutarate and oxaloacetate into aspartate. Artificially increasing oxaloacetate concentration shifts the reaction to the right, decreasing glutamate levels in the blood.