[Effect of repeated injections of GABA on the GABA shunt and various associated reactions in the rat brain].

Effect of repeated administrations of gamma-amino butyric acid (GABA) at doses corresponding to those which are used in clinical medicine, on the state of GABA-shunt and intensity of alpha-ketoglutarate dehydrogenase and aminotransferase reactions as well as on the level of GABA and glutamate was studied in cerebellum, cortex and trunkus cerebri of rat brain. Administration of GABA (5 injections at a dose of 5 mg/kg) caused distinct alterations in central nervous system, which involved activation of GABA-transaminase, utilizing GABA, and inactivation of glutamate decarboxylase, producing the amine, as well as a decrease of GABA and glutamate levels and an increase in alpha-ketoglutarate utilization and activation of aminotransferase reactions. These alterations were especially distinct in cerebellum, where initial high intensity of GABA shunt functioning and minimal level of GABA were observed. The alterations observed suggest the existence of pronounced stimulating effect of GABA, even at low doses, on reactions of energy metabolism in brain.