Oxidative and nitrosative stress in the diaphragm of patients with COPD.

Hanneke J.H. Wijnhoven*, Leo M.A. Heunks, Maartje C.P. Geraedts, Theo Hafmans, José R. Viña, P. N.Richard Dekhuijzen

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

COPD is associated with an increased load on the diaphragm. Since chronic muscle loading results in changes in antioxidant capacity and formation of reactive oxygen and reactive nitrogen species, we hypothesized that COPD has a similar effect on the diaphragm, which is related to the severity of COPD. Catalase activity was determined spectrophotometrically. Levels of 4-hydroxy-2-nonenal (HNE)-protein adducts and 3-nitrotyrosine (NT) formation were measured using western blotting. Levels of malondialdehyde (MDA) were assessed by high-performance liquid chromatography. We found that catalase activity was approximately 89% higher in the diaphragm of severe COPD patients (FEV1 37+/-5% predicted) compared with non-COPD patients. MDA levels, a marker for lipid peroxidation, were significantly lower in the diaphragm of COPD patients compared with non-COPD patients, whereas the level of HNE-protein adducts was equal in both groups. NT formation was not different between groups. However, increasing hyperinflation and NT formation were inversely correlated. These results indicate that in COPD the diaphragm adapts to a higher work load by increasing catalase activity, resulting in a reduction in oxidative damage to lipids and tyrosine nitration of proteins.

Original languageEnglish
Pages (from-to)173-179
Number of pages7
JournalInternational journal of chronic obstructive pulmonary disease
Volume1
Issue number2
DOIs
Publication statusPublished - 1 Jan 2006

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