Abstract
Background: Studies suggest that physical exercise reduces lung function decline and risk of exacerbations in asthmatic patients. However, the inflammatory lung response involved in exercise during sensitization remains unclear. Aims: To evaluate the effects of aerobic exercise in an experimental model of sensitization and single ovalbumin (OVA) challenge. Methods: Male Swiss mice were divided into 4 groups: mice non-sensitized, non-exposed to OVA or exercise (Control, n=7); animals submitted to moderate treadmill exercise (Exercise, n=6); animals sensitized (OVA 10 µg) and single exposed to aerosolized OVA 1% (30 min) (OVA, n= 6) and animals sensitized, submitted to exercise and single exposed to OVA (OVA+Ex, n=6). 24 hours after a single OVA/saline exposure, anesthetized mice were euthanized and we performed measures of inflammatory cells from bronchoalveolar fluid (BALF), IL-4, IL-5, IL-10, IL-1ra from lung tissue by enzyme-linked immunosorbent assay and qualitative measures of IgG1 and IgE OVA-specific by Passive Cutaneous Anaphylaxis. Results: Exercise decreased total number of cells, as well as eosinophils, neutrophils, lymphocytes and macrophages from BALF in OVA+Ex group (p<0.05). The median of titles of IgE and IgG1 OVA-specific in OVA+Ex group was significant lower than OVA group, and IL-4 and IL-5 were also decreased in OVA+Ex when compared with OVA group (p<0.05). Levels of IL-10 and IL-1ra did not reach significant difference. Conclusion: Our results showed that aerobic physical exercise attenuated the acute lung inflammatory response induced by a single OVA-challenge in sensitized mice, suggesting immunomodulatory properties of exercise on sensitization process in asthma.
- © 2012 ERS