Objective: To study the effect and mechanism of electroacupuncture(EA)combined with treadmill training in rats with skeletal muscle contusion.
Methods: A total of sixty Sprague Dawley rats were randomly divided into normal,model, EA, treadmill, and combination groups (n=12/group). The self-made striking device was used to establish skeletal muscle contusion model. EA was applied at "Zusanli" (ST 36) and Ashi point in the EA group. Treadmill was applied to train rats in the treadmill group. Rats in the combination group were received the above two methods. All the treatment was given once a day until the 3rd and 14th days after injury. The cross-sectional area and diameter of neonatal gastrocnemius muscle cells 14 days after injury were observed by HE staining. The expression levels of mammalian target of rapamycil (mTOR), myogenin (myoG) in gastrocnemius 3 days after injury and gastrocnemius mTOR, Fast myosin skeletal heavy chain (Fast MyHC) 14 days after injury were observed by Western blot.
Results: The cross-sectional area and diameter of neonatal muscle gastrocnemius cells in the model group were significantly lower than those in the normal group (P<0.01), and those in all the intervention groups were significantly higher than those of the model group (P<0.05), with better results in the combination group compared with those in the EA and treadmill groups (P<0.05). On the 3rd day after injury, the expressions of mTOR and myoG proteins in the model group were significantly higher compared with those in the normal group (P<0.01), and those in all the intervention groups were up-regulated in comparison with the model group (all P<0.01). The mTOR and myoG proteins in the treadmill group were lower than those in the EA group (P<0.01). The above two indexes in the combination group were higher than those in the EA and treadmill groups (P<0.05, P<0.01). On the 14th day after injury, the expression of mTOR was up-regulated in the model group compared with that in the normal group, but without significant difference (P<0.05), while the expression of Fast MyHC decreased (P<0.01). The expressions of mTOR and Fast MyHC in all the intervention groups increased compared with those in the model group (P<0.05, P<0.01). The expressions of mTOR and Fast MyHC proteins in the treadmill group were significantly down-regulated compared with those in the EA group (P<0.05, P<0.01). The two indexes in the combination group were higher than those in the other two intervention groups (P<0.01).
Conclusions: EA combined with treadmill training can improve the myogenic differentiation and maturation, alleviate the injury of skeletal muscle, which may be related to its effect of increasing the expression of mTOR protein and positively regulating myoG and Fast MyHC proteins.