Effects of electroacupuncture on the expression of cyclin-dependent kinase 5 after skeletal muscle contusion / 中华物理医学与康复杂志

ABSTRACT

Objective To observe the effect of the electroacupuncture ( EA) on the expression of cyclin-de-pendent kinase 5 ( Cdk5 ) in rats with muscle contusion and to explore its mechanism. Methods Thirty-two Sprague-Dawley rats were randomly divided into a normal group of 4, a model group of 4, a natural recovery group ( NR) of 12 and an EA group of 12. All except those in the normal group had acute skeletal muscle contusion induced through a heavy blow. The EA group was treated with 15 minutes of EA daily beginning 48 h after the injury while the other rats received no EA. The model group was sacrificed 24 h after modeling, and rats from the NR and EA groups were sacrificed on the 7th, 14th and 21st day after the modeling to collect tissues. Hematoxylin eosin ( HE) staining, Western blotting and quantitative real-time fluorescence PCR were used to observe any histological changes, as well as Cdk5 protein and mRNA expression. Results The HE staining showed that the other 3 groups displayed larger a-mounts of muscle fiber fracture, dissolution and inflammatory cell invasion than was observed in the normal group. Compared with the NR group, quicker recovery was seen in the EA group as evidenced by faster muscle satellite cell proliferation and more new muscle fiber generation. The average Cdk5 protein expression in both the NR and EA groups was higher than in the normal group, and that of the EA group was significantly lower than that of the NR group. Conclusions Muscle contusion can increase Cdk5 expression in skeletal muscles, at least in rats. EA can promote the restoration of skeletal muscle function, probably by inhibiting CDK5 protein and mRNA expression.