The impact of aerobic exercise on lung inflammation and remodeling in experimental emphysema

This study investigated the impact of aerobic exercise on lung inflammation and remodeling in experimental emphysema. 32 BALB/c mice were assigned into 2 groups. In control (C) animals, saline was intratracheally ( it ) injected, whereas emphysema mice received porcine pancreatic elastase (ELA, 0.1 UI, it ). Saline and ELA were it injected once a wk during 4 wks. After the last wk, C and emphysema groups were further randomized into subgroups: sedentary and exercise. Exercise mice ran on a motorized treadmill, at moderate intensity (8-12 m.min-1), 5% grade, 30 min/day, 3 times a wk for 4 wks. 24-h after the last session, lung mechanics and morphometry, as well as cytokines and total cell count in bronchoalveolar lavage fluid (BALF) and blood were measured. Echocardiographic analysis was done before and after emphysema induction and at the end of the experiment. The sedentary emphysema group presented, compared to C: 1) reduced lung static elastance; 2) increased lung hyperinflation and elastic fiber content; 3) augmented levels of KC [murine interleukin (IL)-8 homolog], tumor necrosis factor-α, interferon-γ, and IL-10; and 4) pulmonary arterial hypertension, evidenced by increased pulmonary flow acceleration. Aerobic exercise: 1) improved lung mechanics, 2) reduced lung hyperinflation, and the number of cells and levels of these cytokines in BALF and blood, 3) diminished elastic fiber content, and 4) restored pulmonary flow acceleration to C values. In conclusion, in the present elastase-induced emphysema model, 4 weeks of aerobic exercise modulated the inflammatory process and acted on lung remodeling, improving pulmonary function. Supported by: INCT-INOFAR, FAPERJ, PRONEX, CNPq