Study on the mechanism of electroacupuncture stimulation to activate the acupoint effect and promote skeletal muscle repair.

Objective To investigate the mechanism of inducing macrophage polarization induced by acupoint effect of electroacupuncture to promote the repair of acute skeletal muscle injury. Methods 45 SD rats were randomly divided into blank group, model group, electroacupuncture group(EA group), sodium chrominate group (DSCG group) and electroacupuncture + sodium chrominate group (hereinafter referred to as EA + DSCG group), with 9 rats in each group. The rats in the EA group and the EA + DSCG group were subjected to EA intervention at the right "Chengshan" (BL57) and "Yanglingquan" (GB34), with a frequency of 2 Hz/100 Hz. The gait changes of rats were recorded by animal gait analyzer. The morphological changes of the right gastrocnemius were observed by HE staining. The changes of mast cell aggregation and degranulation in local skin muscles of "chengshan" point were observed by toluidine blue staining. The expressions of Pax7, MyoD and skin mast cells and 5-HT in the right gastrocnemius were detected by immunofluorescence method. The positive expressions of CD68 and CD206 in right gastrocnemius macrophage was observed by immunohistochemical staining. Results Compared with blank group, the wiggle time of the right hind leg in model group and DSCG group increased, stride length decreased, HE staining showed inflammatory cell infiltration, myocyte enlargement, degeneration and necrosis. The degranulation rate of local skin mast cells in "Chengshan" (BL57) area increased, and the expressions of mast cell tryptase, 5-HT, Pax7, MyoD, CD68 and CD206 increased (P<0.05). Compared with model group, the wiggle time of the right hind leg in EA group and EA + DSCG group decreased, stride length increased, HE staining showed that inflammatory cell infiltration was reduced, muscle cells were uniform in size and arranged neatly. Mast cell degranulation rate increased significantly in EA group, and the expressions of mast cell tryptase, 5-HT, Pax7, MyoD and CD206 increased (P<0.05), while CD68 expression decreased (P<0.05). Compared with EA + DSCG group, the degranulation rate of mast cells and the expressions of mast cell tryptase, 5-HT, Pax7, MyoD and CD206 increased (P<0.05), while CD68 expression decreased in EA group (P<0.05). Conclusion EA "Chengshan" (BL57) and "Yanglingquan" (GB34) can stimulate acupuncture points to locally induce mast cell degranulation, promote the polarization of macrophages, and then activate muscle satellite cells to play the regulatory process of repairing skeletal muscle injury. [ABSTRACT FROM AUTHOR]