Aerobic training (AT) decreases dyspnoea and exercise-induced bronchospasm, and improves aerobic capacity and quality of life; however, the mechanisms for such benefits remain poorly understood. The aim of the present study was to evaluate the AT effects in a chronic model of allergic lung inflammation in mice after the establishment of airway inflammation and remodelling.Mice were divided into the control group, AT group, ovalbumin (OVA) group or OVA+AT group and exposed to saline or OVA. AT was started on day 28 for 60 min five times per week for 4 weeks. Respiratory mechanics, specific immunoglobulin (Ig)E and IgG 1 , collagen and elastic fibres deposition, smooth muscle thickness, epithelial mucus, and peribronchial density of eosinophils, CD3+ and CD4+, IL-4, IL-5, IL-13, interferon-c, IL-2, IL-1ra, IL-10, nuclear factor (NF)-kB and Foxp3 were evaluated.The OVA group showed an increase in IgE and IgG 1 , eosinophils, CD3+, CD4+, IL-4, IL-5, IL-13, NF-kB, collagen and elastic, mucus synthesis, smooth muscle thickness and lung tissue resistance and elastance. The OVA+AT group demonstrated an increase of IgE and IgG 1 , and reduction of eosinophils, CD3+, CD4+, IL-4, IL-5, IL-13, NF-kB, airway remodelling, mucus synthesis, smooth muscle thickness and tissue resistance and elastance compared with the OVA group (p,0.05). The OVA+AT group also showed an increase in IL-10 and IL-1ra (p,0.05), independently of Foxp3.AT reversed airway inflammation and remodelling and T-helper cell 2 response, and improved respiratory mechanics. These results seem to occur due to an increase in the expression of IL-10 and IL-1ra and a decrease of NF-kB.
