[Effects of Electroacupuncture on Apoptosis-related Protein Expression of Gastrocnemius Muscle Cells in Rats with Denervated Sciatic Nerve].

OBJECTIVE

To observe the anti-apoptosis effect of electroacupuncture (EA) on gastrocnemius muscle cells in rats with denervated sciatic nerve, so as to explore its possible mechanisms underlying delaying atrophy of skeletal muscle.

METHODS

Sixty-three male Sprague-Dawley rats were randomly divided into sham operation group, model group, and EA group, and then further divided into 3 subgroups in each group(=7/subgroup). Gastrocnemius muscle atrophy model was established by transecting the sciatic nerve of rat. EA (5 Hz, 1.5 mA) was applied to "Zusanli" (ST 36) and "Chengshan" (BL 57) acupoints at the affected side for 10 min, once a day for 1, 2, 3 weeks, respectively. The gastrocnemius muscles were sampled on the 7, 14, 21 d after modeling, separately. The apoptotic cells were detected by TUNEL staining. Bcl-2, Bax, Cyt-C and Caspase-3 protein expressions were determined by Western blot. RT-PCR was used to check Caspase-3 gene expression.

RESULTS

Compared with the sham operation group, the cell apoptotic index in gastrocnemius was markedly higher, gastrocnemius Bcl-2 protein expression was markedly down-regulated, and gastrocnemius Bax, Cyt-C and Caspase-3 protein expressions were considerably up-regulated in the model group at all time-points (<0.05). Compared with the model group, the cell apoptotic indexes in gastrocnemius were significantly lower in the three EA subgroups (<0.05). Bcl-2 protein expressions were markedly up-regulated while Bax, Cyt-C and Caspase-3 protein expressions were significantly down-regulated in the EA group 14, 21 days after modeling compared with the corresponding model subgroups (<0.05). The changes of Caspase-3 mRNA expression levels of gastrocnemius in all groups were similar to those of Caspase-3 protein expressions.

CONCLUSIONS

Electroacupuncture intervention can effectively increase Bcl-2 expression and decrease Bax, Cyt-C and Caspase-3 expression in gastrocnemius muscle, and consequently reduce the apoptosis of muscle cell, which may contribute to its effect in delaying the skeletal muscle atrophy of denervated sciatic nerve.