Effect of physical aerobic training in asthma: evaluation in experimental models

Abstract

Asthma is a chronic airway disease with high prevalence and pulmonary rehabilitation seems to have a relevant role in patient's improvement. Physical conditioning (PC) is part of a rehabilitation program and is supervised by respiratory therapists. Despite of asthma's high prevalence, the benefits of PC in asthmatic patients is poorly know if compared with those known on patients with chronic obstructive pulmonary disease. The aim of the present study is to evaluate the effect of distinct PC intensities on chronic allergic airway inflammation using experimental models. After chronic pulmonary allergic sensitization, mice and guinea pigs will be submitted to distinct PC programs. The use of both animal species is necessary due to bronchial hyperresponsiveness and immunological allergic response in each species. Chronic allergic pulmonary sensitization will be performed with ovalbumin (OVA) trough inhalation. PC will be performed on treadmill and animals will be submitted to moderate (50%) or intense (75%) aerobic exercise. After that, animals will be sacrificed and bronchoalveolar lavage (BAL) and lung histopathology will be performed. Total and partial number of cells at the BAL and lung as well as plasmatic and BAL levels of inflammatory mediators will be quantified. Methacolin airway hyperresponsiveness and hyperpnea-induced bronchoconstriction (exercise-induced bronchoconstriction like) will be analyzed in another group of animals submitted to similar experimental protocols. Statistical analysis will be performed by two-way variance analysis test (ANOVA) to every studied parameter and significance level will be adjusted to p0.05. This study should bring new evidences to the importance of physical activity for asthmatic patients and could clarify the most beneficial physical activity intensity to be performed by these patients. (AU)