Effect of training on airways inflammatory response and remodeling in a rat model

Training has many beneficial effects, however few studies report its effects on the lungs. The aim of this study was to assess the effects of acute exercise and exercise training on inflammatory responses and remodeling in central and peripheral airways. Sixteen Sprague-Dawley rats trained for 10 weeks, while 14 rats served as controls. Before sacrifice, 8 trained (TRAC) and 8 untrained control (CONAC) rats underwent a single acute exercise bout, while 8 trained (TR) and 6 untrained control (CON) rats were sacrificed without acute exercise. The central and peripheral airways were morphologically examined for inflammatory cells and immunostained for decorin, collagen I, α-smooth muscle actin. No significant differences were found for morphometric analysis in central and peripheral airways, however CONAC showed a significant increase in polymorphonuclear cells in the central airways compared to CON. In contrast, TRAC did not show an inflammatory response different from TR. A similar trend was present in peripheral airways. Training did not induce differences in airways inflammation and remodeling as compared to CON. However, training seemed to limit the inflammatory response induced by acute exercise in the central airways.

► We studied the effects of training on airways inflammation and remodeling in rats. ► After 10 weeks of training, no differences were found for morphometric analysis. ► Training did not induce differences in airways inflammation and remodeling. ► Contrary to controls, trained rats did not show an inflammatory response to acute exercise. ► Training limited the inflammatory response induced by acute exercise.