High-Intensity Exercise Prevents Disturbances in Lung Inflammatory Cytokines and Antioxidant Defenses Induced by Lipopolysaccharide.

In this study, we evaluated the effects of high-intensity swimming in an experimental model of acute lung injury (ALI) induced by lipopolysaccharide (LPS) on lung inflammation and antioxidant defenses. Balb/C male mice were submitted to exercise (30 min/day, 5 days/week, for a period of 3 weeks) prior to LPS instillation in the lung. Twenty-four hours after delivery of LPS (10 µg/animal), mice were euthanized and bronchoalveolar fluid (BALF) was obtained for cell counting and analysis of cytokines by ELISA. Lung tissue was used to evaluate antioxidant defenses. LPS instillation resulted in an increase in total and mononuclear cells, IL-1ß, TNF-α, and IL-6 in BALF. LPS instillation also altered IL-10 and IL-ra levels in BALF and induced antioxidant defenses (glutathione, superoxide dismutase, catalase, and glutathione peroxidase) in the lung. Protein carbonyl increased in the LPS-treated animals. High-intensity swimming prevented all these changes induced by LPS. Significance: Therefore, this experimental protocol of high-intensity swimming showed a protective effect on ALI, decreasing inflammatory processes and preventing disturbances in antioxidant defenses into the lungs.

Effects of High-Intensity Swimming on Lung Inflammation and Oxidative Stress in a Murine Model of DEP-Induced Injury.

Studies have reported that exposure to diesel exhaust particles (DEPs) induces lung inflammation and increases oxidative stress, and both effects are susceptible to changes via regular aerobic exercise in rehabilitation programs. However, the effects of exercise on lungs exposed to DEP after the cessation of exercise are not clear. Therefore, the aim of this study was to evaluate the effects of high-intensity swimming on lung inflammation and oxidative stress in mice exposed to DEP concomitantly and after exercise cessation. Male Swiss mice were divided into 4 groups: Control (n = 12), Swimming (30 min/day) (n = 8), DEP (3 mg/mL-10 µL/mouse) (n = 9) and DEP+Swimming (n = 8). The high-intensity swimming was characterized by an increase in blood lactate levels greater than 1 mmoL/L between 10th and 30th minutes of exercise. Twenty-four hours after the final exposure to DEP, the anesthetized mice were euthanized, and we counted the number of total and differential inflammatory cells in the bronchoalveolar fluid (BALF), measured the lung homogenate levels of IL-1ß, TNF-α, IL-6, INF-Ï«, IL-10, and IL-1ra using ELISA, and measured the levels of glutathione, non-protein thiols (GSH-t and NPSH) and the antioxidant enzymes catalase and glutathione peroxidase (GPx) in the lung. Swimming sessions decreased the number of total cells (p<0.001), neutrophils and lymphocytes (p<0.001; p<0.05) in the BALF, as well as lung levels of IL-1ß (p = 0.002), TNF-α (p = 0.003), IL-6 (p = 0.0001) and IFN-Ï« (p = 0.0001). However, the levels of IL-10 (p = 0.01) and IL-1ra (p = 0.0002) increased in the swimming groups compared with the control groups, as did the CAT lung levels (p = 0.0001). Simultaneously, swimming resulted in an increase in the GSH-t and NPSH lung levels in the DEP group (p = 0.0001 and p<0.002). We concluded that in this experimental model, the high-intensity swimming sessions decreased the lung inflammation and oxidative stress status during DEP-induced lung inflammation in mice.