Molecular regulation of antioxidant ability in the hippocampus of EL mice
| Autor: | Taku Doi, Yoshiya L. Murashima, Mayuko Takaki, Yuto Ueda, Keiko Nagatomo, Hiroshi Kannan |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
medicine.medical_specialty
Microdialysis Time Factors Amino Acid Transport System y+ Ratón Amino Acid Transport System X-AG Blotting Western Glutamic Acid Endogeny Mice Inbred Strains Hippocampal formation Biology Hippocampus Antioxidants chemistry.chemical_compound Mice Internal medicine Extracellular medicine Hippocampus (mythology) Animals Neurotransmitter Molecular Biology Chromatography High Pressure Liquid General Neuroscience Glutamate receptor Extracellular Fluid Excitatory Amino Acid Transporter 1 Endocrinology chemistry Biochemistry Neurology (clinical) Developmental Biology |
| Zdroj: | Brain research. 1228 |
| ISSN: | 0006-8993 |
| Popis: | We recently found that the antioxidant ability was remarkably decreased in the hippocampus (Hipp) of EL at 8 weeks of age utilizing ESR spectroscopy. In this study, in addition to evaluating the extracellular glutamate concentration, we tried to determine whether or not changes in the expression of cystine/glutamate exchanger (xCT) and glutamate transporter take place in the Hipp of EL. EL mice and DDY mice at 5, 10, and 20 weeks of age were used for Exp. I and II, respectively. Exp. I: During the interictal state, dialysate was collected from the ventral Hipp using a microdialysis technique, and an extracellular concentration of glutamate ([Glu] o ) was measured with HPLC-ECD. Exp. II: The hippocampal expression of the glutamate transporter and xCT was estimated by Western blots. Exp. I: The level of [Glu] o at 10 weeks of age was remarkably higher at other ages of EL mice, while [Glu] o of DDY was unchanged as a result of age. Exp. II: The excitatory amino acid carrier-1 (EAAC-1) and xCT of EL mice at 10 weeks of age decreased more than those of DDY. GLAST and GLT-1 of EL mice at 5 weeks of age decreased more than those of DDY at the same age. No differences were found between EL and DDY for GLAST and GLT-1 at other ages. According to previous studies, the decreased endogenous antioxidant potential observed at 10 weeks of age is a very likely explanation for ictogenesis. The decreased xCT expression at 10 weeks of age could provide the molecular mechanism to explain the depletion of the endogenous antioxidant ability of EL mice during ictogenesis. In addition to the depletion of antioxidant ability, decreased EAAC-1 at this period could be one reason for the collapse of the molecular action of inhibition. These molecular findings support the idea that the elevation of [Glu] o at 10 weeks of age triggers ictogenesis. |
| Databáze: | OpenAIRE |
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