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Alteration of Amino Acid Metabolism in Epileptogenic Mice by Elevation of Brain Pyridoxal Phosphate
Author(s) -
Norris D. K.,
Murphy R. A.,
Chung S. H.
Publication year - 1985
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1985.tb08776.x
Subject(s) - glutamate decarboxylase , pyridoxal , pyridoxal phosphate , glutamate receptor , medicine , endocrinology , gaba transaminase , chemistry , convulsion , intraperitoneal injection , transaminase , amino acid , metabolism , biochemistry , biology , epilepsy , phosphate , enzyme , cofactor , receptor , neuroscience
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 γ‐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 B 6 ‐deficient feed and cellulose.