RESUMO
Experimental studies have reported that aerobic exercise after asthma induction reduces lung inflammation and remodeling. Nevertheless, no experimental study has analyzed whether regular/moderate aerobic training before the induction of allergic asthma may prevent these inflammatory and remodeling processes. For this purpose, BALB/c mice (n = 96) were assigned into non-trained and trained groups. Trained animals ran on a motorized treadmill at moderate intensity, 30 min/day, 3 times/week, for 8 weeks, and were further randomized into subgroups to undergo ovalbumin sensitization and challenge or receive saline using the same protocol. Aerobic training continued until the last challenge. Twenty-four hours after challenge, compared to non-trained animals, trained mice exhibited: (a) increased systolic output and left ventricular mass on echocardiography; (b) improved lung mechanics; (c) decreased smooth muscle actin expression and collagen fiber content in airways and lung parenchyma; (d) decreased transforming growth factor (TGF)-ß levels in bronchoalveolar lavage fluid (BALF) and blood; (e) increased interferon (IFN)-γ in BALF and interleukin (IL)-10 in blood; and (f) decreased IL-4 and IL-13 in BALF. In conclusion, regular/moderate aerobic training prior to allergic asthma induction reduced inflammation and remodeling, perhaps through increased IL-10 and IFN-γ in tandem with decreased Th2 cytokines.
