The contribution of thioredoxin-2 reductase and glutathione peroxidase to H(2)O(2) detoxification of rat brain mitochondria.
Biochim Biophys Acta
; 1817(10): 1901-6, 2012 Oct.
Article
em En
| MEDLINE
| ID: mdl-22398128
ABSTRACT
Brain mitochondria are not only major producers of reactive oxygen species but they also considerably contribute to the removal of toxic hydrogen peroxide by the glutathione (GSH) and thioredoxin-2 (Trx2) antioxidant systems. In this work we estimated the relative contribution of both systems and catalase to the removal of intrinsically produced hydrogen peroxide (H(2)O(2)) by rat brain mitochondria. By using the specific inhibitors auranofin and 1-chloro-2,4-dinitrobenzene (DNCB), the contribution of Trx2- and GSH-systems to reactive oxygen species (ROS) detoxification in rat brain mitochondria was determined to be 60±20% and 20±15%, respectively. Catalase contributed to a non-significant extent only, as revealed by aminotriazole inhibition. In digitonin-treated rat hippocampal homogenates inhibition of Trx2- and GSH-systems affected mitochondrial hydrogen peroxide production rates to a much higher extent than the endogenous extramitochondrial hydrogen peroxide production, pointing to a strong compartmentation of ROS metabolism. Imaging experiments of hippocampal slice cultures showed on single cell level substantial heterogeneity of hydrogen peroxide detoxification reactions. The strongest effects of inhibition of hydrogen peroxide removal by auranofin or DNCB were detected in putative interneurons and microglial cells, while pyramidal cells and astrocytes showed lower effects. Thus, our data underline the important contribution of the Trx2-system to hydrogen peroxide detoxification in rat hippocampus. This article is part of a Special Issue entitled 17th European Bioenergetics Conference (EBEC 2012).
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tiorredoxina Dissulfeto Redutase
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Proteínas Mitocondriais
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Glutationa Peroxidase
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Hipocampo
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Peróxido de Hidrogênio
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Mitocôndrias
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Proteínas do Tecido Nervoso
Limite:
Animals
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article