Alteration of Amino Acid Metabolism in Epileptogenic Mice by Elevation of Brain Pyridoxal Phosphate |
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Authors: | D K Norris R A Murphy S H Chung |
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Institution: | National Institute for Medical Research, Mill Hill, London, England |
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Abstract: | 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. |
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Keywords: | Epilepsy Amino acid metabolism Glutamate decarboxylase Vitamin B6 Pyridoxal-5'-phosphate γ-Aminobutyric acid transaminase |
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