Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/198449
Type: Artigo de periódico
Title: Mitochondrial Atp-sensitive K(+) Channels As Redox Signals To Liver Mitochondria In Response To Hypertriglyceridemia.
Author: Alberici, Luciane C
Oliveira, Helena C F
Paim, Bruno A
Mantello, Camila C
Augusto, Amanda C
Zecchin, Karina G
Gurgueira, Sonia A
Kowaltowski, Alicia J
Vercesi, Anibal E
Abstract: We have recently demonstrated that hypertriglyceridemic (HTG) mice present both elevated body metabolic rates and mild mitochondrial uncoupling in the liver owing to stimulated activity of the ATP-sensitive potassium channel (mitoK(ATP)). Because lipid excess normally leads to cell redox imbalance, we examined the hepatic oxidative status in this model. Cell redox imbalance was evidenced by increased total levels of carbonylated proteins, malondialdehydes, and GSSG/GSH ratios in HTG livers compared to wild type. In addition, the activities of the extramitochondrial enzymes NADPH oxidase and xanthine oxidase were elevated in HTG livers. In contrast, Mn-superoxide dismutase activity and content, a mitochondrial matrix marker, were significantly decreased in HTG livers. Isolated HTG liver mitochondria presented lower rates of H(2)O(2) production, which were reversed by mitoK(ATP) antagonists. In vivo antioxidant treatment with N-acetylcysteine decreased both mitoK(ATP) activity and metabolic rates in HTG mice. These data indicate that high levels of triglycerides increase reactive oxygen generation by extramitochondrial enzymes that promote mitoK(ATP) activation. The mild uncoupling mediated by mitoK(ATP) increases metabolic rates and protects mitochondria against oxidative damage. Therefore, a biological role for mitoK(ATP) as a redox sensor is shown here for the first time in an in vivo model of systemic and cellular lipid excess.
Subject: Animals
Disease Models, Animal
Female
Hypertriglyceridemia
Male
Mice
Mice, Transgenic
Mitochondria, Liver
Oxidation-reduction
Potassium Channels
Reactive Oxygen Species
Citation: Free Radical Biology & Medicine. v. 47, n. 10, p. 1432-9, 2009-Nov.
Rights: fechado
Identifier DOI: 10.1016/j.freeradbiomed.2009.08.013
Address: http://www.ncbi.nlm.nih.gov/pubmed/19703550
Date Issue: 2009
Appears in Collections:Unicamp - Artigos e Outros Documentos

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