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 3groups were further allocated to 0h

24 h and 48hsubgroups(n=8in each subgroup).The acute soft tissue contusion model was established by using 500g-counterweight free falling hitting at the GM of the right leg(height 30cm).The Ashi-point was punctured with a piece of filiform needle by penetrating the site beside the injured GM

and stimulated for about 5seconds.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 hand 48h.Compared with the normal control group

HGF protein expression levels of GM at the 3time-points in the model group

and at 48 hin 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 downregulated at 24 hand 48hafter 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.