Pharmacological studies upon the production of glutamic acid and glutamine in the brain.

Weil-Mahlherbe (1) reported in 1936 that glutamic acid is the only amino acid which can be absorbed and assimilated in the brain. Since that time there has been developed the clinical application of glutamic acid to brain diseases. For instance, it is reported that the glutamic acid intravenously infused can relieve or cure hypogly cemic coma (2) ; when administered orally, it shows a striking curative effect on a patient of intelligence deficiency with mongolism (3, 4), idiot, underdevelopment of brain and so on (3), relieves the fit of epilepsia, and promotes the psychological and intelligent growth of children (3). Moreover, some reports refer to important physiological actions of glutamic acid such as to effect the convulsion on the central nervous system (3, 5) or to activate the choline-acetylase and so on (3, 6). On the other hand, as to the process of which glutamic acid and glutamine are produced, more knowledge is remained blank. Schwerin et al. (7) stated that the glutamic acid intravenously injected did not result in an increase of glutamic acid or glutamine in the brain. Brain, anyway, is an organ richest in the glutamic acid content, ranking next to kidney. For example, brain contains 50 times as much glutamic acid, and 10 times as much glutamine as blood has (7). Thus we come to the question from what substance and how is this great deal of glutamic acid and glutamine produced in this organ. Herein my exprimentation is directed to pursue the formation process of them from the pharmacological standpoint.