[The effect of acupuncture stimulation of Ashi-point on hepatocyte growth factor expression in the soft tissue in acute contusion rats].

OBJECTIVE: To observe the effect of acupuncture stimulation of Ashi-point on hepatocyte growth factor (HGF) protein expression in gastrocnemius muscle (GM) in rats with traumatic injury of GM, so as to reveal its mechanism underlying improvement of traumatic injury of skeletal muscle. METHODS: A total of 80 SD rats were randomly divided into normal control (n = 8), model, acupuncture control, and acupuncture treatment groups, and the latter 3 groups were further allocated to 0 h, 24 h and 48 h subgroups (n = 8 in each subgroup). The acute soft tissue contusion model was established by using 500 g-counterweight free falling hitting at the GM of the right leg (height 30 cm). The Ashi-point was punctured with a piece of filiform needle by penetrating the site beside the injured GM, and stimulated for about 5 seconds. For acupuncture control group, acupuncture was performed in the same Ashi-point in normal rats. Pathological changes of the focal GM were observed by H. E. staining and HGF protein expression of GM was detected by Western blot. RESULTS: H.E. staining showed that different degrees of injury of GM tissue including broken muscle fibers with cellular swelling, inflammatory cell infiltration, muscle fibrinolysis, atrophy, degeneration and necrosis, etc., were found at each time-point after modeling, while in the acupuncture treatment group, the severity of muscle injury was relatively milder particularly at the time-points of 24 h and 48 h. Compared with the normal control group, HGF protein expression levels of GM at the 3 time-points in the model group, and at 48 h in the acupuncture control group were markedly increased (P<0.05, P<0.01); while in comparison with the model group, HGF protein expression levels were remarkably down-regulated at 24 h and 48 h after acupuncture treatment (P<0.01, P<0.05). CONCLUSION: Acupuncture stimulation of Ashi-point can significantly down-regulate HGF protein expression in the GM in soft tissue contusion rats, which may contribute to its effects in relieving contusion injury of skeletal muscle.