Comparison of effects of routine electroacupuncture and pre-electroacupuncture in improving lung function in acute lung injury rats

Abstract

To observe the effect of electroacupuncture (EA) and pre-EA at"Taiyuan"(LU9) on histopathological changes, pulmonary ventilation function, pneodynamics, and contents of TNF-α, IL-1β and IL-10 in the bronchoalveolar lavage fluid in rats with acute lung injury (ALI), in order to explore their differences of therapeutic effects. A total of 92 male SD rats were randomly divided into control, model, routine EA and pre-EA groups, with 23 rats in each group. The ALI rat model was established by instillation of 0.5% lipopolysaccharide solution (5 mg/kg) intratracheally. EA (3 mA, 10 Hz) was applied to bilateral LU9 for 20 min, once 5 h after modeling for rats of the routine EA group, and once on the 1st, 3rd and 5th day respectively before modeling for rats of the pre-EA group. The pulmonary ventilation functions, including dynamic lung compliance (Cdyn), tidal volume (TV)，minute ventilation volume (MV), lung resistance, peak inspiratory flow (PIF), peak expiratory flow (PEF), were measured by using a small animal lung function detection system. The electromyogram (EMG) of the diaphragm muscle was recorded for observing changes of the total integral electromyogram(iEMG), single iEMG and respiration rate. Pathological changes of the lung tissue were scored after H.E. staining. The contents of TNF-α, IL-1β and IL-10 in the bronchoalveolar lavage fluid were determined by enzyme linked immunosorbent assay. Compared with the control group, the Cdyn, TV, MV and PIF consi-derably decreased (P<0.000 1), and the lung resistance, total iEMG of diaphragm muscle, lung injury score, and contents of TNF-α and IL-1β were significantly increased (P<0.05, P<0.001, P<0.01) in the model group. In comparison with the model group, the TV, MV and PIF in both routine EA and pre-EA groups,and the Cdyn, total iEMG and single iEMG in the routine EA group, as well as the IL-10 content in the pre-EA group were significantly increased (P<0.01, P<0.001, P<0.05), whereas the lung injury score, and contents of TNF-α and IL-1β were significantly decreased in the pre-EA group (P<0.05). Both pre-EA and routine EA at LU9 can improve the lung function of ALI model rats. Pre-electroacupuncture is related to local immunoregulation, while electroacupuncture is mainly related to the improvement of pulmonary ventilation function and respiratory motility.