Hydroxyl radical generation dependent on extracellular ascorbate in rat striatum, as determined by microdialysis
| Autor: | Shuichi Hara, Takahiko Endo, Hajime Mizukami, Fumi Kuriiwa |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Male
medicine.medical_specialty Microdialysis Antioxidant Gentisates medicine.medical_treatment Ascorbic Acid Striatum Toxicology Rats Sprague-Dawley chemistry.chemical_compound Internal medicine Hydroxybenzoates Extracellular medicine Animals Behavior Animal Hydroxyl Radical Chemistry Ascorbic acid Dehydroascorbic Acid Corpus Striatum Rats Deferoxamine Endocrinology Biochemistry Systemic administration Hydroxyl radical Extracellular Space medicine.drug |
| Zdroj: | Toxicology. 258:10-16 |
| ISSN: | 0300-483X |
| Popis: | Ascorbate (AA), an antioxidant substance known as vitamin C, exists in the brain at a high concentration, although transfer into the brain after systemic administration of AA itself is limited. Intraperitoneal administration of dehydroascorbate (DHA) resulted in a rapid and progressive increase in extracellular AA in rat striatum in a dose-dependent manner. DHA administration increased 2,3- and 2,5-dihydroxybenzoate (2,3- and 2,5-DHBA) formation from salicylate in parallel with the increase in extracellular AA. Intrastriatal administration of active AA oxidase (AAO), but not the inactivated enzyme, completely suppressed the increase in 2,3- and 2,5-DHBA formation after the DHA administration. These findings suggest that extracellular AA might stimulate hydroxyl radical (OH) generation in the striatum. This is supported by the observation of dose-dependent OH generation upon intrastriatal administration of AA itself. In addition, deferoxamine, an iron chelator, decreased basal 2,3- and 2,5-DHBA formation and strongly, though not completely, suppressed the DHA-induced increase of 2,3- and 2,5-DHBA formation. Therefore, increased extracellular AA might function as a prooxidant and stimulate OH generation in cooperation with iron in rat striatum. |
| Databáze: | OpenAIRE |
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