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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

DELAYED URIC ACID ACCUMULATION IN PLASMA PROVIDES ADDITIONAL ANTIOXIDANT PROTECTION AGAINST IRON-TRIGGERED OXIDATIVE STRESS AFTER A WINGATE TEST

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Autor(es):
Souza-Junior, T. P. [1] ; Lorenco-Lima, L. [2] ; Ganini, D. [3] ; Vardaris, C. V. [2] ; Polotow, T. G. [2] ; Barros, M. P. [2]
Número total de Autores: 6
Afiliação do(s) autor(es):
[1] Fed Univ Parana UFPR, Dept Phys Educ, Curitiba, Parana - Brazil
[2] Cruzeiro do Sul Univ, Inst Phys Act & Sports Sci ICAFE, Postgrad Program Human Movement Sci, Sao Paulo - Brazil
[3] NIEHS, Free Rad Metab Grp, Lab Toxicol & Pharmacol, Res Triangle Pk, NC 27709 - USA
Número total de Afiliações: 3
Tipo de documento: Artigo Científico
Fonte: BIOLOGY OF SPORT; v. 31, n. 4, p. 271-276, 2014.
Citações Web of Science: 7
Resumo

Reactive oxygen species are produced during anaerobic exercise mostly by Fe ions released into plasma and endothelial/muscle xanthine oxidase activation that generates uric acid (UA) as the endpoint metabolite. Paradoxically, UA is considered a major antioxidant by virtue of being able to chelate pro-oxidative iron ions. This work aimed to evaluate the relationship between UA and plasma markers of oxidative stress following the exhaustive Wingate test. Plasma samples of 17 male undergraduate students were collected before, 5 and 60 min after maximal anaerobic effort for the measurement of total iron, haem iron, UA, ferric-reducing antioxidant activity in plasma (FRAP), and malondialdehyde (MDA, biomarker of lipoperoxidation). Iron and FRAP showed similar kinetics in plasma, demonstrating an adequate pro-/antioxidant balance immediately after exercise and during the recovery period (5-60 min). Slight variations of haem iron concentrations did not support a relevant contribution of rhabdomyolysis or haemolysis for iron overload following exercise. UA concentration did not vary immediately after exercise but rather increased 29% during the recovery period. Unaltered MDA levels were concomitantly measured. We propose that delayed UA accumulation in plasma is an auxiliary antioxidant response to post-exercise (iron-mediated) oxidative stress, and the high correlation between total UA and FRAP in plasma (R-Square = 0.636; p = 0.00582) supports this hypothesis. (AU)

Processo FAPESP: 02/09405-9 - Estudo da atividade antioxidante da astaxantina em lipossomos unilamelares: bloqueando radicais livres e afetando a permeabilidade da membrana?
Beneficiário:Marcelo Paes de Barros
Linha de fomento: Auxílio à Pesquisa - Apoio a Jovens Pesquisadores