Effects of acupuncture at opposite acupoints on expression of hepatocyte growth factor in rats with skeletal muscle contusion

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.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- daysubgroup, 3- daysubgroup, 5- daysubgroup and 7- daysubgroup, 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 of ashipoints at health side for 15 min, once a day. The subgroups of opposing needling group were treated for 1 day, 3 days, 5 daysand 7 days, respectively. No treatment was given in the model group. Samples were collected in the subgroups 1 day, 3 days, 5 daysand 7 daysafter treatment. The morphological change of injured gastrocnemius musclewas 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.① The results of HE staining showed that, 1 dayafter contusion, the inflammatory cells of gastrocnemius musclein the opposing needling group were less than those in the model group; 3 daysand 5 daysafter contusion, myoblasts and myotubes in the opposing needling group were more than those in the model group; 7 daysafter 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 daysand 5 daysafter contusion, the positive cell rate of PCNA in the opposing needling group was significantly higher than that in the model group (all P<0.001); 7 daysafter contusion, the positive cell rate of PCNA in the opposing needling group was significantly less than that in the model group (P<0.001). ③ The results of Western blot showed that, 1 day, 3 daysand 5 daysafter contusion, the expression of HGF protein and PCNA protein in the opposing needling group was significantly higher than that in the model group (all P<0.05); 7 daysafter contusion, the expression of HGF protein and PCNA protein in the opposing needling group was significantly lower than that in the model group (all P<0.05).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.