Total antioxidant capacity is impaired in different structures from aged rat brain.
Our data support a disproportion between free radicals levels and scavenging systems activity in different cerebral regions of the aging rat. We investigated the total reactive antioxidant potential and reactivity levels, which represent the total antioxidant capacity, in different cerebral regions of the aging rat (cortex, striatum, hippocampus and the cerebellum). In addition, we have determined several oxidative stress parameters, specifically the free radicals levels, the macromolecules damage (lipid peroxidation and carbonyl content), as well as the antioxidant enzymes activities in different cerebral areas from young (2 months-old), mature adult (6 months-old) and old (24 months-old) male Wistar rats. Free radicals levels, determined by 2',7'-dichlorofluorescein diacetate probe, were higher in striatum, cerebellum and hippocampus from aged rats. There was an age-related increase in lipoperoxidation in hippocampus and cerebral cortex. In the cerebellum, a high activity of superoxide dismutase and a decrease of catalase activity were observed. The striatum exhibited a significant catalase activity decrease; and glutathione peroxidase activity was diminished in the hippocampus of mature and aged rats. There was a marked decrease of total antioxidant capacity in hippocampus in both reactivity and potential levels, whereas striatum and cerebral cortex displayed a reduction on reactivity assay. We suggest that age-related variations of total antioxidant defenses in brain may predispose structures to oxidative stress-related neurodegenerative disorders.
Siqueira
Ionara Rodrigues
IR
Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil. ionara@ufrgs.br
Fochesatto
Cíntia
C
de Andrade
Aline
A
Santos
Melissa
M
Hagen
Martine
M
Bello-Klein
Adriane
A
Netto
Carlos Alexandre
CA
D000367:Age Factors; D000375:Aging / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D001921:Brain / Q000033:anatomy & histology / Q000201:enzymology / Q000378:metabolism*; D001923:Brain Chemistry; D002374:Catalase / Q000378:metabolism*; D002839:Chromans / Q000378:metabolism*; D005452:Fluoresceins / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism*; D015227:Lipid Peroxidation / Q000502:physiology; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D056913:Mediator Complex Subunit 1; D050050:Protein Carbonylation / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism
D002839:Chromans; D005452:Fluoresceins; C538857:Med1 protein, rat; D056913:Mediator Complex Subunit 1; D017392:Thiobarbituric Acid Reactive Substances; D014157:Transcription Factors; C029569:diacetyldichlorofluorescein; D008315:Malondialdehyde; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid