Effects of aerobic physical training in obese asthmatic mice

Abstract

Asthma is a chronic airways inflammatory disease, characterized mainly by the presence of eosinophils, Th2 lymphocytes, mastocytes and dendritic cells. The airways of asthmatics also present remodeling and hyperresponsiveness. In the last years, a growing number of studies have shown that the prevalence of asthma between the obese population is significantly higher compared with non-obese population. The physical training, particularly the aerobic physical training, present anti-inflammatory effects to the airways of the asthmatics as well as reduces systemic inflammation in obese subjetcs. Therefore, the present study aims to evaluate, using experimental model of asthma in obese mice, the effects of aerobic physical training on airways inflammation, remodeling and hyperresponsiveness. To this 96 male C57Bl/6 obese mice, weighing between 18-22 grams, will be distributed in the following groups (n = 8/group): Control obese (CO), Exercise obese (EO), Asthma obese (AO), Exercise asthma obese (EAO). The animals will be initially submitted to high caloric and high fat diet (55% satured fat, 29% carbohidrates and 16% proteins) during 10 weeks, followed by the induction of asthma by using house dust mite (Dermatophagoides pteronyssinus - HDM), which will composed by the administration of 100ug of HDM per mouse through intra-tracheal via, once a week, during 8 weeks. The aerobic physical training will be performed in a treadmill (60% of maximal intensity, 25% of incline, 1h/session, 5x/week, 4 weeks), begining after the third HDM administration, during 4 weeks. The parameters to be evaluated will be the physical capacity, the bronchial hyperresponsiveness, the celularity in the bronchoalveolar lavage, the number of eosinophils, lymphocytes, macrophages and neutrophils in the airways wall, the airways remodeling, the levels of cytokines (Th1, Th2, Th17) and the levels of adipokines (leptin, adiponectin and resistin) in the bronchoalveolar lavage and in the serum. (AU)