title: Age-related regional changes in hydroxyl radical stress and antioxidants in gerbil brain.
abstract: The levels of hydroxyl radicals and oxidized GSH have been examined as indices of oxidative stress in young (3 months), middle-aged (15 months), and old (20-24 months) gerbil brain hippocampus, cortex, and striatum. The hydroxyl radical stress was estimated by measuring the salicylate hydroxyl radical trapping products 2,5- and 2,3-dihydroxybenzoic acid. The stress was significantly higher in all three brain regions in middle-aged and old gerbils versus young animals (< or = 66.0%). Regional comparisons showed that the stress was significantly higher in cortex than in either the hippocampus or striatum of the middle-aged and old gerbils (< or = 32.0%). The ratio of oxidized to total GSH also increased progressively in middle-aged and old animals in all three brain regions (p < 0.05, < or = 41.1%), further indicating a general age-related increase in oxidative stress. Parallel to this age-related increase in oxidative stress, a significant, albeit slight (8%), decrease in neuronal number in hippocampal CA1 region was observed in both the middle-aged and old animals. Possible differences in antioxidant levels were also examined. Total GSH levels were similar across age groups (variance < 12%). However, the regional comparison showed that it was highest in striatum in all age groups. The levels of alpha-tocopherol (vitamin E) were significantly higher in the middle-aged and old animals in all three regions (< or = 70.4%). Vitamin E was highest in the hippocampus and the differences between the hippocampus and the cortex and striatum increased with age.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Upjohn Company, Kalamazoo, MI 49001.
authors.forename: J R
authors.initials: JR
authors.lastname: Zhang
authors.forename: P K
authors.initials: PK
authors.lastname: Andrus
authors.forename: E D
authors.initials: ED
authors.lastname: Hall
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000378:metabolism; D001834:Body Water / Q000378:metabolism; D001921:Brain / Q000254:growth & development / Q000378:metabolism*; D002540:Cerebral Cortex / Q000254:growth & development / Q000378:metabolism; D003342:Corpus Striatum / Q000254:growth & development / Q000378:metabolism; D005841:Gentisates; D005849:Gerbillinae; D005978:Glutathione / Q000378:metabolism; D006624:Hippocampus / Q000254:growth & development / Q000378:metabolism; D062385:Hydroxybenzoates / Q000378:metabolism; D017665:Hydroxyl Radical / Q000378:metabolism*; D008297:Male; D009474:Neurons / Q000378:metabolism*; D009928:Organ Specificity; D010084:Oxidation-Reduction; D011712:Pyramidal Tracts / Q000378:metabolism; D014810:Vitamin E / Q000378:metabolism
chemical_list: D000975:Antioxidants; D005841:Gentisates; D062385:Hydroxybenzoates; D014810:Vitamin E; D017665:Hydroxyl Radical; C009135:2,3-dihydroxybenzoic acid; D005978:Glutathione; D001205:Ascorbic Acid; C010925:2,5-dihydroxybenzoic acid