HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Free Full Text (PDF) Free All Versions of this Article: 100/2/555    most recent 00780.2005v1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (10) Citing Articles via Google Scholar Google Scholar Articles by Barreiro, E. Search for Related Content PubMed PubMed Citation Articles by Barreiro, E.

Respiratory loading intensity and diaphragm oxidative stress: N-acetyl-cysteine effects

¹Muscle and Respiratory System Research Unit and Pneumology Department, Institut Municipal d'Investigacio Medica, Hospital del Mar, Pompeu Fabra University, Barcelona, Catalonia; ²Pneumology Department and Research Unit, Cruces Hospital, Basque Country University, Barakaldo, Basque Country, Spain; and ³Critical Care and Respiratory Divisions, Royal Victoria Hospital and Meakins-Christie Laboratories, McGill University, Montreal, Quebec, Canada

Submitted 1 July 2005 ; accepted in final form 26 September 2005

We hypothesized that resistive breathing of moderate to high intensity might increase diaphragm oxidative stress, which could be partially attenuated by antioxidants. Our objective was to assess the levels of oxidative stress in the dog diaphragm after respiratory muscle training of a wide range of intensities and whether N-acetyl-cysteine (NAC) might act as an antioxidant. Twelve Beagle dogs were anesthetized with 1% propophol, tracheostomized, and subjected to continuous inspiratory resistive breathing (IRB) (2 h/day for 2 wk). They were further divided into two groups (n = 6): NAC group (oral NAC administration/24 h for 14 days) and control group (placebo). Diaphragm biopsies were obtained before (baseline biopsy) and after (contralateral hemidiaphragm) IRB and NAC vs. placebo treatment. Oxidative stress was evaluated in all diaphragm biopsies through determination of 3-nitrotyrosine immunoreactivity, protein carbonylation, hydroxynoneal protein adducts, Mn-SOD, and catalase, using immunoblotting and immunohistochemistry. Both protein tyrosine nitration and protein carbonylation were directly related to the amount of the respiratory loads, and NAC treatment abrogated this proportional rise in these two indexes of oxidative stress in response to increasing inspiratory loads. A post hoc analysis revealed that only the diaphragms of dogs subjected to high-intensity loads showed a significant increase in both protein tyrosine nitration and carbonylation, which were also significantly reduced by NAC treatment. These results suggest that high-intensity respiratory loading-induced oxidative stress may be neutralized by NAC treatment during IRB in the canine diaphragm.

inspiratory loading; respiratory muscles; 3-nitrotyrosine; protein carbonylation; antioxidants

This article has been cited by other articles:

				E Barreiro, R Rabinovich, J Marin-Corral, J A Barbera, J Gea, and J Roca Chronic endurance exercise induces quadriceps nitrosative stress in patients with severe COPD Thorax, January 1, 2009; 64(1): 13 - 19. [Abstract] [Full Text] [PDF]

				L. F. Ferreira and M. B. Reid Muscle-derived ROS and thiol regulation in muscle fatigue J Appl Physiol, March 1, 2008; 104(3): 853 - 860. [Abstract] [Full Text] [PDF]