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OBJECTIVE: To observe the therapeutic effect of electroacupuncture (EA) of "Zusanli" (ST36) and "Ashi"-point on the healthy side (opposing needling) on muscular injury and expression of myogenin (myoG) and fast myosin skeletal heavy chain (Fast MyHC) proteins in the gastrocnemius muscle (GM) tissues in skeletal muscle contusion rats，so as to explore its mechanism underlying improvement of skeletal muscle injury. METHODS: A total of 54 male SD rats were divided into normal control (n ＝ 6)，model (n＝24) and opposing needling (EA, n＝24) groups. The latter two groups were further randomized into 3, 5, 7 and 14 d subgroups (n＝6 per subgroup). The skeletal muscle contusion model of the hind-limb was established by using a self-made striking device. EA (1 Hz/3 Hz，1－2 mA) was applied to ST36 and "Ashi"-point on the uninjured side of the hind-limb for 15 min every time, once a day for 3, 5, 7 and 14 days, respectively. The injured GM was harvested on the 3rd, 5th, 7th and 14th day after muscular contusion. The morphological changes of the injured GM and the mean cross-sectional areas (CSAs) of the neonatal muscle cells were observed by microscope after H．E. staining. The immunoactivity of desmin protein (myogenic marker protein of myoblast cell) of GM was detected by immunofluorescence stain on the 7th day after injury, and the expression levels of myoG (on the 3rd and 5th day after injury) and fast MyHC protein of GM tissues (on the 7thand 14th day after injury) were detected by Western blot. RESULTS: H．E. staining of GS tissue showed fewer neuronal myocytes with disordered arrangement at different sizes, and appearance of some collagenous fibers among the mesenchyme on day 7 and 14 after muscular contusion, which was relatively milder in the EA group. In the EA group, the CSA values of the neonatal muscle cells were significantly larger than those in the model group on the day 7th (P0.05). On the 3rd and 5th day after muscular contusion, the expression level of myoG protein was significantly up-regulated in the model group compared with the normal control group (P<0.001), and significantly up-regulated in the EA group than that in the model group (P<0.001). On the 7th and14th day after contusion, the expression level of fast MyHC protein was significantly down-regulated in the model group relevant to the normal control group (P<0.001), and markedly up-regulated in the EA group relevant to the model group (P<0.01)．. CONCLUSION: EA of ST36 and "Ashi"-point on the contralateral limb can up-regulate the expression of myoG and fast MyHC proteins of GM in acute skeletal muscle contusion rats, which may contribute to its effect in promoting the repair of skeletal muscle injury.
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<p><b>OBJECTIVE</b>To observe the effects of acupuncture at opposite acupoints on expression of hepatocyte growth factor (HGF) in rats with skeletal muscle contusion, and to explore the mechanism of acupuncture at opposite acupoints on skeletal muscle contusion.</p><p><b>METHODS</b>Fifty-four Sprague Dawley (SD) rats were randomly divided into a blank group (6 rats), a model group (24 rats) and an opposing needling group (24 rats). The model group and opposing needling group were further divided into 1-day subgroup, 3-day subgroup, 5-day subgroup and 7-day subgroup, 6 rats in each one. No intervention was given in the blank group, while the model of skeletal muscle contusion was established in the model group and opposing needling group by self-made contusion device. 24 hours after contusion, electroacupuncture (EA) was applied at "Zusanli" (ST 36) and the corresponding points ofpoints at health side for 15 min, once a day. The subgroups of opposing needling group were treated for 1 day, 3 days, 5 days and 7 days, respectively. No treatment was given in the model group. Samples were collected in the subgroups 1 day, 3 days, 5 days and 7 days after treatment. The morphological change of injured gastrocnemius muscle was observed by using microscope after HE staining. The positive cell rate of proliferating cell nuclear antigen (PCNA) was detected by immunohistochemistry. The expression levels of HGF protein and PCNA protein were observed by Western blot.</p><p><b>RESULTS</b>① The results of HE staining showed that, 1 day after contusion, the inflammatory cells of gastrocnemius muscle in the opposing needling group were less than those in the model group; 3 days and 5 days after contusion, myoblasts and myotubes in the opposing needling group were more than those in the model group; 7 days after contusion, the neonatal muscle cells in the opposing needling group were more than those in the model group. ② The results of immunohistochemistry showed that, 1 day, 3 days and 5 days after contusion, the positive cell rate of PCNA in the opposing needling group was significantly higher than that in the model group (all<0.001); 7 days after contusion, the positive cell rate of PCNA in the opposing needling group was significantly less than that in the model group (<0.001). ③ The results of Western blot showed that, 1 day, 3 days and 5 days after contusion, the expression of HGF protein and PCNA protein in the opposing needling group was significantly higher than that in the model group (all<0.05); 7 days after contusion, the expression of HGF protein and PCNA protein in the opposing needling group was significantly lower than that in the model group (all<0.05).</p><p><b>CONCLUSION</b>Acupuncture at opposite acupoints could regulate the expression of HGF and promote the activation, proliferation, migration and differentiation of muscle satellite cells in rats with skeletal muscle contusion, which could speed up the process of skeletal muscle injury repair.</p>
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Objective To investigate the relationship between wound age and the expressions of frizzled-2 (Fzd2) mRNA and its protein in rats skeletal muscle after contusion,and to explore its possibility of being an index for wound age estimation.Methods The mRNA and protein expressions of Fzd2 in rats skeletal muscle of the control group and the experimental group within 4-48 h after contusion were detected per 4 h by RT-qPCR and Western blotting.Results The relative expression of Fzd2 mRNA increased at 24h,36h and 40h after contusion,and the expression at 24h was twice as the control group (P＜0.05).The relative expression of Fzd2 protein changed inconspicuously after contusion (P＞0.05).Conclusion The changes of Fzd2 mRNA expression after contusion in a certain time can be a basis to estimate wound age by combined multi-indicators.
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Objective To observe the effect of different interventions on muscle healing following contusion by electromyographical signal, and functionally to study the significance of electromyographical technique in evaluating the healing quality of skeletal muscle after injuries. Methods A standard contusion model was developed at the right gastrocnemius by specific device in 108 male rats. The animals were divided into three groups:group IGF-1,local injection by exogenous IGF-1 at injured site; group Chinese medicine treated with the injection of Huangqidanshen, and group natural healing for control. EMG signals of gastrocnemius, such as fibrillation potentials, positive sharp waves as well as the latency and wave-amplitude of compound muscle action potentials (CMAPs) were probed, recorded and compared at day 2、5、7、10、14、21、28、35 and 56 after injury respectively. Results (1) Fibrillation potentials and positive sharp waves were discovered at day 2 to 5 after contusion, and reached its peak by day 7 to 10, and then normalized gradually around the 35th day with muscle healing in group natural healing. Above abnormal signals disappeared much more early in group IGF-1, then that in group Chinese medicine. (2) The latency and wave-amplitude of CMAP shown a gradual recovery process with muscle healing. The recovery tendency was most rapid in group IGF-1, slower in group Chinese medicine, and latest in group natural healing. (3) The wave-amplitude of CMAP approached to normal in group IGF-1 by 8 weeks following contusion, a little bit later in group Chinese medicine groups, and lastly in group natural healing. Conclusions(1) Electromyographical study verified that IGF-1 and Huangqidanshen could improve healing and functional recovery following muscle injury. IGF-1 was a much more strong intervention for healing promotion. (2) EMG is an useful tool in evaluating the healing process and healing quality of skeletal muscle.