Aerobic exercise attenuates pulmonary injury induced by exposure to cigarette smoke

Abstract

It has recently been suggested that regular exercise reduces lung function decline and risk of chronic obstructive pulmonary disease (COPD) among active smokers; however, the mechanisms involved in this effect remain poorly understood.The present study evaluated the effects of regular exercise training in an experimental mouse model of chronic cigarette smoke exposure.Male C57BL/6 mice were divided into four groups (control, exercise, smoke and smoke+exercise). For 24 weeks, we measured respiratory mechanics, mean linear intercept, inflammatory cells and reactive oxygen species (ROS) in bronchoalveolar lavage (BAL) fluid, collagen deposition in alveolar walls, and the expression of antioxidant enzymes, matrix metalloproteinase 9, tissue inhibitor of metalloproteinase (TIMP)1, interleukin (IL)-10 and 8-isoprostane in alveolar walls.Exercise attenuated the decrease in pulmonary elastance (p,0.01) and the increase in mean linear intercept (p50.003) induced by cigarette smoke exposure. Exercise substantially inhibited the increase in ROS in BAL fluid and 8-isoprostane expression in lung tissue induced by cigarette smoke. In addition, exercise significantly inhibited the decreases in IL-10, TIMP1 and CuZn superoxide dismutase induced by exposure to cigarette smoke. Exercise also increased the number of cells expressing glutathione peroxidase.Our results suggest that regular aerobic physical training of moderate intensity attenuates the development of pulmonary disease induced by cigarette smoke exposure.

Interaction between Physical Activity and Smoking on Lung, Muscle, and Bone in Mice

“…In line with other observations, smoking induced fiber atrophy (30, 31) and resulted in the loss of muscle mass (32) whilst it did not affect muscle contractility (23). Additionally, the shift towards a more glycolytic profile in both muscles, as shown before (23,33,34), did not result in impaired maximal exercise capacity, which is in agreement with other mouse studies (17,34) but contrasting with the data in patients with COPD (35). Discrepancies may be due to the fact that the mouse model of cigarette smoke exposure induced a mild form of human lung disease.…”

Body size and physical activity in relation to incidence of chronic obstructive pulmonary disease

“…Relevant biologic mechanisms are speculative, but they include physical activity-induced reductions in oxidative stress 35 and chronic inflammation, 36 factors that promote COPD. In addition, physical activity improves processes of lung repair 37 and reduces obesity. 38 In our study, the inverse effect estimates for physical activity were strongest among those who currently smoked, and they became progressively less pronounced across strata of those who smoked in the recent past, distant past and never.…”

Terapia celular em modelo experimental do enfisema pulmonar induzido por meio de fumaça de cigarro.

“…Entre as diferentes abordagens para indução do enfisema pulmonar em modelos experimentais, o método de indução por exposição à fumaça de cigarro, vem ganhando maior destaque na literatura, considerando que este modelo aproxima-se e busca mimetizar, de forma mais fidedigna as características fisiopatológicas da doença humana (Cendon et al, 1997;Huh et al, 2011;Jardim et al, 2010;March et al, 2000;Nikula et al, 2000;Toledo et al, 2011;Xu et al, 2004;Zheng et al, 2009). …”

“…A fumaça de cigarro promove a ativação de mediadores inflamatórios, como macrófagos e neutrófilos, desencadeando a produção de enzimas que favorecem o desequilíbrio entre proteases e antiproteases, levando ao alargamento dos espaços aéreos e consequente destruição do parênquima pulmonar (Anciães et al, 2011;Toledo et al, 2011;Wright et al, 2008 (Gosker et al, 2009;Guerassimov et al, 2003;Maeno et al, 2007;Marumo et al, 2009;Rinaldi et al, 2011;Schweitzer et al, 2011 (Foronjy et al, 2005). Posteriormente, Wrigth et al…”