Moderate aerobic exercise training attenuates inflammatory response to streptococus pneumoniae in mice

Streptococus pneumoniae is one of the most important causes of morbidity and mortality in respiratory diseases. Aerobic exercise is known to attenuate inflammatory processes in some lung injuries. Objectives: To study if moderate exercise training prior to bacterial infection alters the pulmonary inflammatory profile. Methods: 40 Balb/C mice (14-16 weeks) were divided into 4 groups: Control (C), Aerobic Exercise (AE), S. pneumonia infection (P), S. pneumonia + Aerobic Exercise (P+AE). Moderate intensity treadmill training was performed over 4 weeks, 5 time/wk, 60 min/session in the AE and P+AE groups. After 72 hs of the last exercise training session, P and P+AE groups were challenged intranasally with pneumococcal strains M10 (type 11A) through the inoculation of 50 μl of the suspension of the bacteria in 0.9% saline. C group did not receive intranasal instillation or exercise training. Bronchoalveolar lavage (BAL) was performed 10 days after the intranasal challenge to quantify the number of total cells, macrophages, neutrophils and lymphocytes. Results: S. pneumonia inoculation resulted in increase number of total cells (18.63×10 4 cels/mL ± 9.02; p 4 cels/mL ± 1.94; p 4 cels/mL ± 6.84; p S. pneumonia inoculated animals resulted in significantly decrease in total number of cells (10.15×10 4 cels/mL ± 1.10; p 4 cels/mL ± 0.84; p=0.003) in BAL. Conclusion: These results suggest that moderate aerobic exercise training attenuated the neutrophilic inflammation in an animal model of bacterial infection.Supported by FAPESP, LIMHC-FMUSP, CNPq, Brazil.