In order to study the mechanism of glutamic acids involved in the metabolisms of pyruvate and α-ketoglutaric acid in blood, spinal fluid of lumbar region, and ventricle fluid, the author gave oral administration of dailydosage of 15 g sodium glutamate for five days to schizophrenic patients without any apparent disorders of organs, and determined the amounts of both acids in blood when the patients were at rest both before and after the sodium glutamate administration. Then after lobotomy, blood, spinal fluid of lumbar regions and ventricle Fluid were drawn and the contents of both acids in these fluids were determined in the same manner as mentioned above. As the results: 1. In the estimations of both acids in the blood drawn both before and after the administration of sodium glutamate to the patient at rest, no fixed tendency suggestive of the effect of this drug could be recognized. 2. In the cases where lobotomy had been performed after administration of sodium glutamate and the contents of both acids were determined, and the following results were obtained: 1. The amount of pyruvate in blood=1.00±0.06 mg/dl; the amount of α-ketoglutarate in blood=0.41±0.06 mg/dl; the amount of pyruvate in spinal fluid of lumbar region=0.69±0.02 mg/dl; the amount of α-ketoglutaric acid in spinal fluid of lumbar region=0.35±0.03 mg/dl; pyruvate in ventricle fluid=0.80±0.02 mg/dl; and α-ketoglutaric acid in ventricle fluid=1.83±0.13 mg/dl. On comparing each of these values with respective values of the control reported in Part 1, both amounts of pyruvate and α-ketoglutaric acid in blood and spinal fluid of lumbar region show a decreasing tendency. This phenomenon seems to be due to the tranquilizing effect of sodium glutamate on the central nervous system or to improved liver function due to this drug. On the other hand, in the case of the ventricle fluid the pyruvate content was less than that in the control, and the content of α-ketoglutaric acid was somewhat increased. This fact seems to indicate that glutamic acid is involved in the metabolism of ketoacid in the cerebral fluid and is also associated with the glutamic acid metabolism in the brain, and also it is suggestive of some significance relative to the supply of glutamic acids in the brain.