Função pulmonar e depuração mucociliar nasal de cortadores de cana-de-açúcar brasileiros expostos à queima de biomassa / Lung function and nasal mucociliary clearance in Brazilian sugarcane cutters exposed to biomass burning

Resumo Objetivos: avaliar a função pulmonar e a depuração mucociliar nasal de cortadores de cana-de-açúcar. Métodos: foram avaliados dezesseis cortadores de cana-de-açúcar em dois períodos: durante o plantio da cana-de-açúcar, em abril/2011, e no final da safra, no período de queima e colheita manual da cana-de-açúcar, outubro/2011. A função pulmonar e a depuração mucociliar foram avaliadas por meio da espirometria e do teste de tempo de trânsito da sacarina (TTS), respectivamente. Resultados: a função pulmonar apresentou diminuição no %FEF25-75 [99,31 (23,79) até 86,36 (27,41); p = 0,001]; %VEF1 [92,19 (13,24) até 90,44 (12,76); p = 0,022] e VEF1/CVF [88,62 (5.68) até 84,90 (6.47); p = 0,004] no período da colheita em comparação ao de plantio. Também houve uma diminuição significativa no resultado do teste do TTS na colheita [3 (1) min] em comparação ao plantio [8 (3) min] (p < 0,001). Conclusão: os cortadores de cana-de-açúcar apresentaram diminuição do %FEF25-75, %VEF1, do índice VEF1/CVF, e aumento da velocidade do transporte mucociliar nasal no final do período de colheita.

Abstract Objective: to evaluate the effects of sugarcane burning on lung function and mucociliary clearance in sugarcane workers. Methods: sixteen sugarcane workers were evaluated in two sequential periods: during the non-harvest season, in April/2011, and during the sugarcane burning harvest season, in October/2011. Mean values (standard deviation) of lung function and mucociliary clearance were evaluated through spirometry and the saccharin transit time (STT) test, respectively. Results: lung function decreased %FEF25-75 [99.31 (23.79) to 86.36 (27.41); p = 0.001]; %FEV1 [92.19 (13.24) to 90.44 (12.76); p = 0.022]; and FEV1/FVC [88.62 (5.68) to 84.90 (6.47); p = 0.004] during the harvest season compared with the non-harvest season. A significant decrease was found in saccharin transit time during the harvest [3 (1) min] season compared with the non-harvest season [8 (3) min] (p < 0.001). Conclusion: sugarcane workers present a decrease in %FEF25-75, %FEV1, FEV1/FVC ratio, and increase in nasal mucociliary transport velocity at the end of the harvest season.

Sakuranetin reverses vascular peribronchial and lung parenchyma remodeling in a murine model of chronic allergic pulmonary inflammation.

BACKGROUND AND PURPOSE: Asthma is a disease of high prevalence and morbidity that generates high costs in hospitalization and treatment. Although the airway is involved in the physiopathology of asthma, there is also evidence of the importance of vascular and lung parenchyma inflammation and remodeling, which can contribute to the functional pulmonary alterations observed in asthmatic patients. Our aim was to evaluate treatment using sakuranetin, a flavone isolated from the twigs of Baccharis retusa (Asteraceae), on vascular and lung parenchyma alterations in an experimental murine model of asthma. METHODS: Male BALB/c mice were subjected to a sensitization protocol with ovalbumin for 30days and were treated with or without sakuranetin (20mg/kg/mice) or dexamethasone (5mg/kg/mice); then, the lungs were collected for histopathological analysis. We evaluated extracellular matrix remodeling (collagen and elastic fibers), inflammation (eosinophils and NF-kB) and oxidative stress (8-isoprostane) in the pulmonary vessels and lung parenchyma. The thickness of the vascular wall was quantified, as well as the vascular endothelial growth factor (VEGF) levels. RESULTS: We demonstrated that sakuranetin reduced the number of eosinophils and elastic fibers in both the pulmonary vessels and the lung parenchyma, probably due to a reduction of oxidative stress and of the transcription factor NF-kB and VEGF levels in the lung. In addition, it reduced the thickness of the pulmonary vascular wall. The treatment had no effect on the collagen fibers. In most of the parameters, the effect of sakuranetin was similar to the dexamethasone effect. CONCLUSIONS AND IMPLICATIONS: Sakuranetin had anti-inflammatory and antioxidant effects, preventing vascular and distal parenchyma changes in this experimental model of asthma.

Analysis of autonomic modulation after an acute session of resistance exercise at different intensities in chronic obstructive pulmonary disease patients.

PURPOSE: Physical exercises are employed as part of the treatment of patients with chronic obstructive pulmonary disease (COPD); however information regarding cardiac autonomic modulation after an acute session of resistance exercise (RE) is unknown. The aim of this study was to evaluate the cardiac autonomic modulation, via heart rate variability after an acute session of RE applied at different intensities in COPD patients. PATIENTS AND METHODS: Twelve COPD patients underwent an acute session of RE with an intensity of 60% and another of 90% of the one repetition maximum test. For analysis of autonomic modulation, heart rate was recorded beat-by-beat for 20 minutes at rest and after the training session. Heart rate variability indexes were obtained in the time and frequency domains for the assessment of autonomic modulation. RESULTS: Regardless of exercise intensity, RE acute sessions influenced the autonomic modulation when the recovery period was compared with the baseline. An increase in standard deviation of normal to normal RR intervals was observed throughout recovery time after the RE, as compared to baseline in both protocols: 60% and 90% of the one repetition maximum test. The spectral component of low frequency index (ms) was higher throughout recovery when compared to baseline in both protocols. The same was also observed in the spectral component of high frequency index (ms) for the protocols of 60% and 90%. CONCLUSION: RE sessions impact on the autonomic modulation of COPD patients by promoting differences in the recovery period compared to baseline, regardless of the intensity of the exercise performed.

Diesel exhaust particulates affect cell signaling, mucin profiles, and apoptosis in trachea explants of Balb/C mice.

Particulate matter from diesel exhaust (DEP) has toxic properties and can activate intracellular signaling pathways and induce metabolic changes. This study was conducted to evaluate the activation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) and to analyze the mucin profile (acid (AB(+) ), neutral (PAS(+) ), or mixed (AB/PAS(+) ) mucus) and vacuolization (V) of tracheal explants after treatment with 50 or 100 µg/mL DEP for 30 or 60 min. Western blot analyses showed small increases in ERK1/2 and JNK phosphorylation after 30 min of 100 µg/mL DEP treatment compared with the control. An increase in JNK phosphorylation was observed after 60 min of treatment with 50 µg/mL DEP compared with the control. We did not observe any change in the level of ERK1/2 phosphorylation after treatment with 50 µg/mL DEP. Other groups of tracheas were subjected to histological sectioning and stained with periodic acid-Schiff (PAS) reagent and Alcian Blue (AB). The stained tissue sections were then subjected to morphometric analysis. The results obtained were compared using ANOVA. Treatment with 50 µg/mL DEP for 30 min or 60 min showed a significant increase (p < 0.001) in the amount of acid mucus, a reduction in neutral mucus, a significant reduction in mixed mucus, and greater vacuolization. Our results suggest that compounds found in DEPs are able to activate acid mucus production and enhance vacuolization and cell signaling pathways, which can lead to airway diseases.

Effects of cigarette smoking intensity on the mucociliary clearance of active smokers.

BACKGROUND: Smoking impairs mucociliary clearance and increases respiratory infection frequency and severity in subjects with and without smoking-related chronic lung diseases. OBJECTIVE: This study evaluated the effects of smoking intensity on mucociliary clearance in active smokers. METHODS: Seventy-five active smokers were grouped into light (1-10 cigarettes/day; n = 14), moderate (11-20 cigarettes/day; n = 34) and heavy smokers (≥21 cigarettes/day; n = 27) before starting a smoking cessation programme. Smoking behaviour, nicotine dependence, pulmonary function, carbon monoxide in exhaled air (exCO), carboxyhaemoglobin (COHb) and mucociliary clearance measured by the saccharin transit time (STT) test were all evaluated. An age-matched non-smoker group (n = 24) was assessed using the same tests. RESULTS: Moderate (49 ± 7 years) and heavy smokers (46 ± 8 years) had higher STT (p = 0.0001), exCO (p < 0.0001) and COHb (p < 0.0001) levels compared with light smokers (51 ± 15 years) and non-smokers (50 ± 11 years). A positive correlation was observed between STT and exCO (r = 0.4; p < 0.0001), STT and cigarettes/day (r = 0.3, p = 0.02) and exCO and cigarettes/day (r = 0.3, p < 0.01). CONCLUSION: Smoking impairs mucociliary clearance and is associated with cigarette smoking intensity.

Avaliação da qualidade de vida relacionada à saúde de cortadores de cana-de-açúcar nos períodos de entressafra e safra / Assessment of health-related quality of life of sugarcane cutters in the pre-harvest and harvest periods / Evaluación de la calidad de vida relacionada con la salud de cortadores de caña de azúcar en los períodos de entre-cosecha y cosecha

OBJETIVO: Avaliar a qualidade de vida relacionada à saúde de cortadores de cana-de-açúcar. MÉTODOS: Estudo longitudinal em uma usina sucroalcooleira no Oeste do estado de São Paulo de abril (final da entressafra) a outubro (final da safra) de 2010. Foram avaliados 44 cortadores de cana-de-açúcar tabagistas e não tabagistas em três períodos: ao final da entressafra, no fim do terceiro mês de safra e no final da safra. A qualidade de vida relacionada à saúde foi avaliada pelo questionário Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). Foram realizados análise de variância para medidas repetidas e teste de Friedman para comparar a qualidade de vida entre os períodos. Utilizou-se o teste de Goodman para identificar a frequência dos trabalhadores cujo escore aumentou nos períodos de safra em comparação com a entressafra (respondedores positivos), considerando-se as variáveis qualitativas dos domínios do SF-36. RESULTADOS: Ao final da entressafra, 23% dos trabalhadores desistiram do trabalho; 27% eram tabagistas. Houve decréscimo significativo no domínio vitalidade no final da safra em comparação com a entressafra. Os desistentes apresentaram maior escore no domínio aspecto social em relação ao grupo que permaneceu no trabalho. Não houve diferença na qualidade de vida relacionada à saúde entre tabagistas e não tabagistas. No entanto, observou-se maior percentual de respondedores positivos entre não tabagistas nos domínios aspecto físico, social e emocional nos três meses de safra e nos domínios estado geral de saúde e aspecto social nos seis meses de safra, quando comparados aos tabagistas. CONCLUSÕES: A qualidade de vida relacionada à saúde em cortadores de cana-de-açúcar mostrou-se diminuída após o período de safra no domínio vitalidade. Os trabalhadores que permaneceram na safra são os que apresentaram piores aspectos sociais, o que mostra a necessidade de promoção de políticas assistencialistas de saúde a essa população específica, principalmente durante a safra canavieira.

OBJECTIVE: To assess health-related quality of life in sugarcane cutters. METHODS: Longitudinal study conducted in a sugar and ethanol plant located in the western region of the State of São Paulo (Southeastern Brazil) from April (pre-harvest) to October (harvest) 2010. A total of 44 sugarcane cutters, smokers and non-smokers, was evaluated in three periods: pre-harvest, at the end of the third month during harvest and at the end of harvest. Health-related quality of life was assessed by the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). Analysis of variance for repeated measures and the Friedman test were performed to compare quality of life among the periods. To identify the frequency of workers whose score increased in the harvest periods compared to pre-harvest (positive responders), the Goodman test was used, considering the qualitative variables of the SF-36 domains. RESULTS: At the end of pre-harvest, 23% workers drop out of work; 27% were smokers. There was a significant decrease in the vitality domain at the end of harvest compared to pre-harvest. The dropouts presented higher score in the social aspect domain compared to the group that remained working. There was no difference in health-related quality of life between smokers and non-smokers. However, there was a higher percentage of positive responders among non-smokers in the physical, social and emotional domains in the third month of harvest and in the general health status and social domains at the end of harvest, compared to smokers. CONCLUSIONS: Health-related quality of life in sugarcane cutters was reduced after the harvest period in the vitality domain. The individuals who remained working during harvest are those with lower scores for social aspects, which demonstrates the need to promote health assistance policies for this specific population, particularly during sugar harvest.

OBJETIVO: Evaluar la calidad de vida relacionada con la salud de cortadores de caña de azúcar. MÉTODOS: Estudio longitudinal en una fábrica de alcohol y subproductos de la caña de azúcar en el Oeste del Estado de Sao Paulo de abril (final de la entre-cosecha) a octubre (final de la cosecha) de 2010. Se evaluaron 44 cortadores de caña de azúcar tabaquistas y no tabaquistas en tres períodos: al final de la entre-cosecha, al final del tercer mes de la cosecha y al final de la cosecha. La calidad de vida relacionada con la salud fue evaluada por el cuestionario Medical Outcomes Study 36-item Short-Form Health Survey (SF-36). Se realizaron análisis de varianza para medidas repetidas y prueba de Friedman para comparar la calidad de vida entre los períodos. Se utilizó la prueba de Goodman para identificar la frecuencia de los trabajadores cuyo escore aumentó en los períodos de cosecha en comparación con la entre-cosecha (respondedores positivos), considerándose las variables cualitativas de los dominios del SF-36. RESULTADOS: Al final de la entre-cosecha, 23% de los trabajadores desistieron del trabajo; 27% eran tabaquistas. Hubo disminución significativa en el dominio vitalidad en el final de la cosecha en comparación con la entre-cosecha. Los disidentes presentaron mayor escore en el dominio aspecto social con relación al grupo que permaneció en el trabajo. No hubo diferencia en la calidad de vida relacionada con la salud entre tabaquistas y no tabaquistas. Sin embargo, se observó mayor porcentaje de respondedores positivos entre no tabaquistas en los dominios aspecto físico, social y emocional en los tres meses de cosecha y en los dominios estado general de salud y aspecto social en los seis meses de cosecha, al compararlos con los tabaquistas. CONCLUSIONES: La calidad de vida relacionada con la salud en cortadores de caña de azúcar se mostró disminuida posterior al período de cosecha en el dominio vitalidad. Los trabajadores que permanecieron en la cosecha presentaron peores aspectos sociales, mostrando la necesidad de promoción de políticas asistencialistas de salud a dicha población específica, principalmente durante la cosecha de caña.

Anti-inflammatory effects of aerobic exercise in mice exposed to air pollution.

PURPOSE: Exposure to diesel exhaust particles (DEP) results in lung inflammation. Regular aerobic exercise improves the inflammatory status in different pulmonary diseases. However, the effects of long-term aerobic exercise on the pulmonary response to DEP have not been investigated. The present study evaluated the effect of aerobic conditioning on the pulmonary inflammatory and oxidative responses of mice exposed to DEP. METHODS: BALB/c mice were subjected to aerobic exercise five times per week for 5 wk, concomitantly with exposure to DEP (3 mg·mL(-1); 10 µL per mouse). The levels of exhaled nitric oxide, reactive oxygen species, cellularity, interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α) were analyzed in bronchoalveolar lavage fluid, and the density of neutrophils and the volume proportion of collagen fibers were measured in the lung parenchyma. The cellular density of leukocytes expressing IL-1ß, keratinocyte chemoattractant (KC), and TNF-α in lung parenchyma was evaluated with immunohistochemistry. The levels of IL-1ß, KC, and TNF-α were also evaluated in the serum. RESULTS: Aerobic exercise inhibited the DEP-induced increase in the levels of reactive oxygen species (P < 0.05); exhaled nitric oxide (P < 0.01); total (P < 0.01) and differential cells (P < 0.01); IL-6 and TNF-α levels in bronchoalveolar lavage fluid (P < 0.05); the level of neutrophils (P < 0.001); collagen density in the lung parenchyma (P < 0.05); the levels of IL-6, KC, and TNF-α in plasma (P < 0.05); and the expression of IL-1ß, KC, and TNF-α by leukocytes in the lung parenchyma (P < 0.01). CONCLUSIONS: We conclude that long-term aerobic exercise presents protective effects in a mouse model of DEP-induced lung inflammation. Our results indicate a need for human studies that evaluate the pulmonary responses to aerobic exercise chronically performed in polluted areas.

[Assessment of health-related quality of life of sugarcane cutters in the pre-harvest and harvest periods]. / Avaliação da qualidade de vida relacionada à saúde de cortadores de cana-de-açúcar nos períodos de entressafra e safra.

OBJECTIVE: To assess health-related quality of life in sugarcane cutters. METHODS: Longitudinal study conducted in a sugar and ethanol plant located in the western region of the State of São Paulo (Southeastern Brazil) from April (pre-harvest) to October (harvest) 2010. A total of 44 sugarcane cutters, smokers and non-smokers, was evaluated in three periods: pre-harvest, at the end of the third month during harvest and at the end of harvest. Health-related quality of life was assessed by the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). Analysis of variance for repeated measures and the Friedman test were performed to compare quality of life among the periods. To identify the frequency of workers whose score increased in the harvest periods compared to pre-harvest (positive responders), the Goodman test was used, considering the qualitative variables of the SF-36 domains. RESULTS: At the end of pre-harvest, 23% workers drop out of work; 27% were smokers. There was a significant decrease in the vitality domain at the end of harvest compared to pre-harvest. The dropouts presented higher score in the social aspect domain compared to the group that remained working. There was no difference in health-related quality of life between smokers and non-smokers. However, there was a higher percentage of positive responders among non-smokers in the physical, social and emotional domains in the third month of harvest and in the general health status and social domains at the end of harvest, compared to smokers. CONCLUSIONS: Health-related quality of life in sugarcane cutters was reduced after the harvest period in the vitality domain. The individuals who remained working during harvest are those with lower scores for social aspects, which demonstrates the need to promote health assistance policies for this specific population, particularly during sugar harvest.

Short-term effects of air pollution from biomass burning in mucociliary clearance of Brazilian sugarcane cutters.

Nasal mucociliary system is the first line of defense of the upper airways and may be affected acutely by exposure to particulate matter (PM) from biomass burning. Several epidemiologic studies have demonstrated a consistent association between levels of air pollution from biomass burning with increases in hospitalization for respiratory diseases and mortality. To determine the acute effects of exposure to particulate matter from biomass burning in nasal mucociliary transport by saccharin transit time (STT) test, we studied thirty-three non-smokers and twelve light smokers sugarcane cutters in two periods: pre-harvest season and 4 h after harvest at the first day after biomass burning. Lung function, exhaled carbon monoxide (CO), nasal symptoms questionnaire and mucociliary clearance (MC) were assessed. Exhaled CO was increased in smokers compared to non-smokers but did not change significantly after harvest. In contrast, STT was similar between smokers and non-smokers and decreased significantly after harvest in both groups (p < 0.001). Exposure to PM from biomass burning did not influence nasal symptoms. Our results suggest that acute exposure to particulate matter from sugarcane burned affects mucociliary clearance in smokers and non-smokers workers in the absence of symptoms.

Reversibility of impaired nasal mucociliary clearance in smokers following a smoking cessation programme.

BACKGROUND AND OBJECTIVE: Smoking cessation (SC) is recognized as reducing tobacco-associated mortality and morbidity. The effect of SC on nasal mucociliary clearance (MC) in smokers was evaluated during a 180-day period. METHODS: Thirty-three current smokers enrolled in a SC intervention programme were evaluated after they had stopped smoking. Smoking history, Fagerström's test, lung function, exhaled carbon monoxide (eCO), carboxyhaemoglobin (COHb) and nasal MC as assessed by the saccharin transit time (STT) test were evaluated. All parameters were also measured at baseline in 33 matched non-smokers. RESULTS: Smokers (mean age 49 ± 12 years, mean pack-year index 44 ± 25) were enrolled in a SC intervention and 27% (n = 9) abstained for 180 days, 30% (n = 11) for 120 days, 49.5% (n = 15) for 90 days or 60 days, 62.7% (n = 19) for 30 days and 75.9% (n = 23) for 15 days. A moderate degree of nicotine dependence, higher education levels and less use of bupropion were associated with the capacity to stop smoking (P < 0.05). The STT was prolonged in smokers compared with non-smokers (P = 0.002) and dysfunction of MC was present at baseline both in smokers who had abstained and those who had not abstained for 180 days. eCO and COHb were also significantly increased in smokers compared with non-smokers. STT values decreased to within the normal range on day 15 after SC (P < 0.01), and remained in the normal range until the end of the study period. Similarly, eCO values were reduced from the seventh day after SC. CONCLUSIONS: A SC programme contributed to improvement in MC among smokers from the 15th day after cessation of smoking, and these beneficial effects persisted for 180 days.

Airway epithelium mediates the anti-inflammatory effects of exercise on asthma.

Airway epithelium plays an important role in the asthma physiopathology. Aerobic exercise decreases Th2 response in murine models of allergic asthma, but its effects on the structure and activation of airway epithelium in asthma are unknown. BALB/c mice were divided into control, aerobic exercise, ovalbumin-sensitized and ovalbumin-sensitized plus aerobic exercise groups. Ovalbumin sensitization occurred on days 0, 14, 28, 42, and aerosol challenge from day 21 to day 50. Aerobic exercise started on day 22 and ended on day 50. Total cells and eosinophils were reduced in ovalbumin-sensitized group submitted to aerobic exercise. Aerobic exercise also reduced the oxidative and nitrosative stress and the epithelial expression of Th2 cytokines, chemokines, adhesion molecules, growth factors and NF-kB and P2X7 receptor. Additionally, aerobic exercise increased the epithelial expression of IL-10 in non-sensitized and sensitized animals. These findings contribute to the understanding of the beneficial effects of aerobic exercise for chronic allergic airway inflammation, suggesting an immune-regulatory role of exercise on airway epithelium.

Low-intensity swimming training partially inhibits lipopolysaccharide-induced acute lung injury.

BACKGROUND: Aerobic exercise decreases pulmonary inflammation and remodeling in experimental models of allergic asthma. However, the effects of aerobic exercise on pulmonary inflammation of nonallergic origin, such as in experimental models of acute lung injury induced by lipopolysaccharide (LPS), have not been evaluated. OBJECTIVE: The present study evaluated the effects of aerobic exercise in a model of LPS-induced acute lung injury. METHODS: BALB/c mice were divided into four groups: Control, Aerobic Exercise, LPS, and Aerobic Exercise + LPS. Swimming tests were conducted at baseline and at 3 and 6 wk. Low-intensity swimming training was performed for 6 wk, four times per week, 60 min per session. Intranasal LPS (1 mg x kg(-1) (60 microg per mouse)) was instilled 24 h after the last swimming physical test in the LPS and Aerobic Exercise + LPS mice, and the animals were studied 24 h after LPS instillation. Exhaled nitric oxide, respiratory mechanics, total and differential cell counts in bronchoalveolar lavage, and lung parenchymal inflammation and remodeling were evaluated. RESULTS: LPS instillation resulted in increased levels of exhaled nitric oxide (P < 0.001), higher numbers of neutrophils in the bronchoalveolar lavage (P < 0.001) and in the lung parenchyma (P < 0.001), and decreased lung tissue resistance (P < 0.05) and volume proportion of elastic fibers (P < 0.01) compared with the Control group. Swim training in LPS-instilled animals resulted in significantly lower exhaled nitric oxide levels (P < 0.001) and fewer neutrophils in the bronchoalveolar lavage (P < 0.001) and the lung parenchyma (P < 0.01) compared with the LPS group. CONCLUSIONS: These results suggest that low-intensity swimming training inhibits lung neutrophilic inflammation, but not remodeling and impaired lung mechanics, in a model of LPS-induced acute lung injury.

Efeitos do treinameno físico aeróbico sobre a lesão pulmonar induzida por exposição à fumaça de cigarro em camundongos C57BI6 / Aerobic exercise attenuates pulmonary alterations induced by exposure to cigarette smoke in mice

O exercício aeróbio foi recentemente descrito como capaz de reduzir a função pulmonar e diminuir o risco de desenvolver DPOC entre fumantes ativos. A plausibilidade biológica da influência da atividade física sobre o declínio da função pulmonar está relacionada aos efeitos anti-inflamatórios efeitos da atividade física, que tem sido descritos em estudos experimentais. A hipótese é que haveria uma interação entre exercício aeróbio e o desenvolvimento da doença. A fim de explorar mais a fisiopatologia da DPOC induzida pela exposição à fumaça de cigarro e os efeitos do exercício no desenvolvimento do enfisema, utilizamos um modelo experimental de DPOC. C57Bl6 foram divididos em quatro grupos: Controle, Fumo, Exercício e Fumo/Exercício. Os animais dos grupos Fumo foram expostos à fumaça de cigarro por 30 minutos por dia, 5 dias por semana, durante 24 semanas. Os animais dos grupos Exercício foram treinados em intensidade moderada durante 60 minutos por dia, 5 dias por semana durante 24 semanas. Os resultados demonstraram que o treinamento físico aeróbio regular de intensidade moderada inibiu o desenvolvimento de enfisema, o aumento do total de células inflamatórias e a produção de espécies reativas de oxigênio no LBA, além do aumento na geração de óxido nítrico exalado, induzido pela exposição à fumaça do cigarro, e inibiu o aumento de 8-isoprostano e MCP1, além de aumentar a expressão da GPx, SODCuZn, TIMP1 e IL-10 por células inflamatórias na parede alveolar...

Aerobic exercise was recently described as capable to reduce lung function decline and risk of developing COPD among active smokers. The biological plausibility of the influence of physical activity on the decline of lung function relies on the anti-inflammatory effects of physical activity, which have been described in experimental studies. We hypothesized there would be an interaction between aerobic exercise and development of disease. In order to further explore the physiopathology of COPD induced by exposure to cigarette smoke and the effects of exercise in development of emphysema, we used an experimental model of DPOC. C57Bl6 were divided in four groups: Control, Smoke, Exercise and Smoke/Exercise. Smoke groups were exposed to cigarette smoke for 30 minutes a day, 5 days a week, for 24 weeks. Exercise groups were trained at moderate intensity exercise for 60 minutes/day, 5 days/week for 24 weeks. The results demonstrated that regular aerobic physical training of moderate intensity inhibited alveolar distension, the increase of total inflammatory cells and production of reactive oxygen species in BAL and the increase in the generation of exhaled nitric oxide induced by exposure to cigarette smoke, and reduced the expression of 8-isoprostane and MCP1 and increased the expression of GPx, SODCuZn, TIMP1 and IL-10 by inflammatory cells in the alveolar wall. The study also showed that aerobic physical training was able to inhibit the decrease in lung elastance induced by exposure to cigarette smoke, but not the content in collagen fibers. These results suggest that regular aerobic physical training of moderate intensity may play an important role during the installation of disease due to its antioxidant and antiinflammatory effects.