ABSTRACT
<p><b>OBJECTIVE</b>Acupuncture has a definite therapeutic effect on chronic obstructive pulmonary disease (COPD), and the cholinergic anti-inflammatory pathway (CAP) has been shown to be involved in regulation of inflammation. In this study, we investigated whether electro-acupuncture (EA) affects the CAP in COPD.</p><p><b>METHODS</b>Sprague-Dawley rats were induced into COPD through exposure to cigarette smoke combined with lipopolysaccharide. EA treatment was applied at Zusanli (ST36) and Feishu (BL13) points for 30 min/d for 7 d. Seventy-two rats were randomly divided into six study groups, including normal, normal + EA, normal + α-bungarotoxin (α-BGT) (the antagonist of the nicotinic acetylcholine receptor α7 subunit (α7nAChR)) + EA, COPD, COPD + EA, and COPD + α-BGT + EA. Lung function, pathology and vagus nerve discharge were tested. The levels of acetylcholine (ACh), acetylcholinesterase (AChE), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in bronchoalveolar lavage fluid (BALF) and lung tissue were measured by enzyme-linked immunosorbent assay. The mRNA and protein expression and immunoreactivity of α7nAChR and its postreceptor inflammation signal pathway, including janus kinase 2 (JAK2), signal transducers and activators of transcription 3 (STAT3), nuclear factor-κB (NF-κB), were observed by quantitative reverse transcription-polymerase chain reaction, Western blot and immunohistochemistry.</p><p><b>RESULTS</b>Compared with normal rats, there were a significant decline in lung function and discharge of the vagus nerve (P < 0.01), a marked sign of lung inflammation and an increase of ACh, AChE, IL-6 and TNF-α level in BALF or lung tissue (P < 0.05, P < 0.01) and higher expression of α7nAChR, JAK2, STAT3 and NF-κB (P < 0.05, P < 0.01) in the COPD rats. In rats receiving EA, the lung function and vagal discharge were enhanced (P < 0.01), lung inflammation was improved and the levels of ACh, AChE, IL-6 and TNF-α were decreased (P < 0.01). Further, the expression of α7nAChR, JAK2, STAT3 and NF-κB was downregulated (P < 0.05, P < 0.01). However, the above effects of EA were blocked in rats injected with α-BGT (P < 0.01).</p><p><b>CONCLUSION</b>EA treatment can reduce the lung inflammatory response and improve lung function in COPD, which may be related to its involvement in the regulation of CAP.</p>
ABSTRACT
Objective:To observe the effect of electroacupuncture (EA) on the expressions of acetylcholine (ACh) and mucin 5AC (MUC5AC) in the lungs of rats with chronic obstructive pulmonary disease (COPD),and explore the mechanism of EA in treating COPD.Methods:Thirty Sprague-Dawley (SD) rats were randomly divided into a control group,a COPD group,and an EA group,with 10 rats in each group.The control group was a group of normal rats.The COPD rat model was induced by cigarette smoke combined with lipopolysaccharide (LPS).The COPD rats were treated with EA at bilateral Feishu (BL 13) and Zusanli (ST 36) in the EA group,30 min each time,once a day,successively for 14 d.The lung function was tested.The contents of ACh and MUC5AC in lungs and bronchoalveolar lavage fluid (BALF) were detected by enzyme-linked immunosorbent assay (ELISA).Pearson method was used to analyze the correlation between pulmonary function and the content of MUC5AC in lungs.The mRNA and protein expressions of MUC5AC in lung tissues were detected by real-time polymerase chain reaction (RT-PCR) and Western blot (WB),respectively.The immune response of MUC5AC was observed by immunohistochemistry.Results:Eight rats were left in each group,and the other two died.Compared with the control group,the total airway resistance (Raw) increased significantly and dynamic compliance (Cdyn) decreased significantly in the COPD group (P＜0.01);compared with the COPD group,the Raw level declined significantly and Cdyn increased significantly in the EA group (P＜0.01).The contents of ACh and MUC5AC in the lungs and BALF were remarkably higher in the COPD group compared with those in the control group (P＜0.01,P＜0.001);compared with the COPD group,the contents of ACh and MUC5AC were significantly lower in the EA group (P＜0.05,P＜0.001).There was a negative correlation between MUC5AC content and lung function (P＜0.001).The mRNA and protein expressions of MUC5AC in the lungs were significantly higher in the COPD group than in the control group (P＜0.001);compared with the COPD group,the expressions were significantly lower in the EA group (P＜0.01).Compared with the control group,the immune response of MUC5AC in the airway epithelium significantly increased in the COPD group (P＜0.001);the immune response of MUC5AC was significantly lower in the EA group compared with that in the COPD group (P＜0.001).Conclusion:EA treatment can improve the lung function of COPD rats,which may be related to its effect in the down-regulation of ACh and MUC5AC contents in the lungs as well as the inhibition of mucus hypersecretion.