Alteration of amino acid metabolism in epileptogenic mice by elevation of brain pyridoxal phosphate.
A single intraperitoneal injection of pyridoxal-5'-phosphate (PLP) in a species of mouse, DBA/2J, that is normally susceptible to sound-induced convulsion exacerbated its epileptic condition. The effect of injection was most pronounced about 30 min after the administration and subsided gradually within the following 4 h. Correlated with this increased seizure susceptibility were enhanced levels of synaptosomal aspartate and glutamate, and a diminished gamma-aminobutyric acid (GABA) level. The concentrations of nonneuroactive amino acids remained unchanged. When stimulated with veratrine, synaptosomes prepared from PLP-injected mice showed an increased release of aspartate and glutamate and a decreased release of GABA compared to those prepared from control mice. The activity of glutamate decarboxylase in the brains of PLP-treated mice was lowered, whereas the activity of GABA-transaminase was enhanced. Finally, the epileptic condition of DBA mice could be ameliorated by maintenance on a diet composed of vitamin B6-deficient feed and cellulose.
D000161:Acoustic Stimulation; D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000378:metabolism*; D051379:Mice; D008815:Mice, Inbred Strains / Q000378:metabolism*; D011732:Pyridoxal Phosphate / Q000378:metabolism*; D012640:Seizures / Q000378:metabolism*; D013574:Synaptosomes / Q000378:metabolism; D026681:Vitamin B 6 Deficiency / Q000378:metabolism
D000596:Amino Acids; D011732:Pyridoxal Phosphate