Effects Of Exercise Intervention On Lung Function And Inflammatory Factors In Lung Tissue Of Rats With COPD

ObjectiveChronic obstructive pulmonary disease（COPD）is a chronic respiratory disease characterized by persistent respiratory symptoms caused by airway and/or alveolar abnormalities resulting from exposure to harmful particulate matter or gases.COPD is associated with chronic inflammation of the airways,regular exercise training has been increasingly recognized as a potential non-pharmacological intervention for the treatment of pulmonary and inflammatory diseases.Currently,the main forms of exercise intervention in COPD include aerobic exercise,resistance exercise,and high-intensity intermittent exercise,but the differences between these exercise interventions have not been clarified.Therefore,in this study,different types of exercise interventions were given to COPD rats to observe the effects of different types of exercise interventions on lung function and inflammatory factors in lung tissues of COPD rats,to investigate the mechanism of the effect of exercise on improving lung function in COPD rats,and to provide reference for exercise rehabilitation in COPD patients in clinical practice.MethodsForty-eight healthy SD rats were randomly divided into control group,model control group,treadmill exercise group,resistance exercise group,high-intensity interval exercise group and swimming exercise group,with 8 rats in each group.The rats in the blank control group were kept in the experimental animal center with normal diet and water,and were not fumigated until the end of the experiment;the rats in the model control group,the runner exercise group,the resistance exercise group,the high-intensity intermittent exercise group and the swimming exercise group were fumigated for 16 weeks with reference to the long-term incremental fumigation exposure method adopted by our group,and the model was judged at the end to ensure successful modeling.The rats in the control group were not exposed to exercise,while the rats in the running,resistance,high-intensity intermittent exercise and swimming exercise groups were exposed to 9 weeks of running,resistance,high-intensity intermittent and swimming exercise,respectively.After the exercise intervention,lung function tests were performed in each of the six groups,and then the lung tissues in the middle of the right lobe were stained with HE for morphological observation,and the levels of inflammatory factors TNF-αand IL-8 in the lung tissues of the six groups were measured by ELISA.Results1.Lung functionCompared with the blank control group,the levels of Cdyn,IC,FVC,FEV₂₀,FEV₅₀,FEV₁₀₀,FEV₂₀₀,and PEF in the model control group decreased significantly with statistically significant differences（P<0.05）;Compared with model control group,FEV20,FEV50,FEV100,PEF and MMEF levels in treadmill exercise group,resistance exercise group,high intensity interval exercise group and swimming exercise group were significantly increased（P<0.05）;Compared with the model control group,the FEV₂₀₀ level of treadmill exercise group,high intensity interval exercise group and swimming exercise group was significantly increased（P<0.05）.In addition,the FVC of the treadmill exercise group and the IC and FVC of the swimming exercise group were also significantly increased compared with the model control group（P<0.05）.Compared with resistance exercise group,FEV50 in swimming exercise group was significantly different（P<0.05）.2.Lung histopathologyIn the lung tissue of the rats in the blank control group,the bronchial and alveolar structures were clear and intact,the alveoli were uniform in size,the airway mucosal epithelial structure was intact,and there was no obvious infiltration of inflammatory cells under the mucosa;in the model control group,the alveolar structure was disorganized,some of the alveolar walls were ruptured and expanded and fused,forming large alveoli,the bronchial epithelium was hyperplastic and thickened,a large number of inflammatory cells gathered under the mucosa,and the number of micro vessels increased significantly;compared with the model control group Compared with the control group,the alveolar structure of the lung tissue of the rats in the treadmill exercise group,resistance exercise group,high-intensity intermittent exercise group and swimming group was less damaged,the bronchial structure was more intact,the submucosal inflammatory cell infiltration was reduced,the wall was thinner,the lumen shape was regular,and the number of micro vessels was reduced.The alveolar cross-sectional area of rats in the model control group was significantly larger than that of rats in the blank control group（P<0.05）;compared with the model control group,the alveolar cross-sectional area of rats in the treadmill exercise group,high-intensity intermittent exercise group,resistance exercise group and swimming exercise group was significantly decreased（P<0.05）,and compared with the other three exercise groups,the alveolar cross-sectional area of rats in the swimming exercise group was significantly decreased（P<0.05）.3.ELISA testCompared with the blank control group,the level of TNF-αin the lung tissue of rats in the model control group increased significantly,and the difference was statistically significant（P<0.05）,and the level of IL-8 tended to increase,but did not reach statistical difference;compared with the model control group,the level of TNF-αin the lung tissue of rats in the treadmill exercise group,high-intensity intermittent exercise group,resistance exercise group and swimming exercise group decreased significantly,and the difference was statistically significant（P<0.05）.IL-8 levels in the lung tissues of the rats in the resistance exercise group decreased significantly compared with the model control group,and the differences were statistically significant（P<0.05）,while IL-8 levels in the lung tissues of the rats in the treadmill exercise group,the high-intensity intermittent exercise group and the swimming exercise group were not significantly different compared with the model control group.ConclusionTreadmill exercise,resistance exercise,high-intensity intermittent exercise and swimming all slowed down the process of airway and lung tissue damage in rats with COPD,and alleviated symptoms of airflow limitation and dyspnea,compared with resistance exercise and high-intensity intermittent exercise.Compared with resistance exercise and high-intensity intermittent exercise,treadmill exercise and swimming had certain advantages in improving lung hyperinflation in rats;treadmill exercise,resistance exercise,high-intensity intermittent exercise and swimming could reduce the level of inflammatory factors in lung tissues of COPD rats and effectively improve lung inflammation in COPD rats.