| Objective:The purpose of this study was to explore the mechanism of electro-acupuncture promoting the reconstruction of neuromuscular junction of skeletal muscle by observing the effect of electro-acupuncture on the expression of MuSK and APP in the process of acute skeletal muscle contusion in rats.
Methods:Fifty-four male SD rats were randomly divided into normal control group (group A, n = 18), model group (group B, n = 18) and electro-acupuncture group (group C, n = 18).The group A was a control group without any treatment, while other groups were established acute skeletal muscle blunt contusion model, by using self-made striking device,group C without electroacupuncture treatment,only had natural recovery.Group C were applied on “Zu Sanli”(ST36) and “Ashi”-piont for 15min every two days . At the 7th, 28th and 56th day after modeling,6 rats were taken from each group at each time point,the morphological changes of rat gastrocnemius muscle were observed by HE staining, and the protein expression of MuSK and APP was detected by Western Blot.
Results: HE stanning showed that the muscle fibers of gastrocnemius muscle of normal rats were arranged neatly and pink, and the size of muscle cells was uniform and neat. On the 7th day after modeling, the gastrocnemius muscle fibers in group B were broken, disarranged and infiltrated with a large number of inflammatory cells.In group C, a small number of newborn muscle cells and muscle fibers were formed and arranged slightly neatly, On the 28th day after modeling, the number of new muscle cells increased and inflammatory cells decreased in group B, and some muscle fibers were formed but arranged irregularly. The muscle fibers in group C increased obviously and arranged neatly, and the muscle fibers in group B were arranged neatly and inflammatory cells decreased greatly on the 56th day after injury. In group C, the injury of gastrocnemius muscle was basically healed and the morphology and structure were basically intact. The results of Western blot showed that the expression levels of MuSK and APP proteins in skeletal muscle of normal rats were lower. After the success of the model, compared with group A, the expression of MuSK and APP protein in skeletal muscle of group B was significantly higher than that of group A (P < 0.05). Compared with group B, the expression of MuSK and APP protein in group C increased on the 7th day after injury, reached the peak on the 28th day, and decreased on the 56th day, and the expression in group C was higher than that in group B at each time point(P< 0.05).
Conclusion: Electro-acupuncture can promote the recovery of skeletal muscle in rats with acute skeletal muscle contusion, and positively regulate the expression of MuSK and APP in the process of skeletal muscle repair, so as to promote the regeneration of NMJ. |
