[Effect of electroacupuncture on the expression of spinal glial fibrillary acidic protein, tumor necrosis factor-alpha and interleukin-1beta in chronic neuropathic pain rats].

OBJECTIVE

To observe the effect of electroacupuncture (EA) on the expression of spinal glial fibrillary acidic protein (GFAP), tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) in chronic constriction injury (CCI) rats.

METHODS

Seventy-two SD rats were randomized into sham operation (sham), CCI (model) and EA groups (n = 24/group). The mechanical and thermal pain thresholds were measured by using Von Frey filaments and radiant-heat irridiation separately. The immunoactivity of GFAP of spinal dorsal horn (L4-L5) was assessed by immunohistochemistry, and the expression of spinal TNF-alpha mRNA and IL-1beta mRNA was detected by real time-PCR.

RESULTS

Compared with pre-CCI and sham group, both mechanical and thermal pain thresholds decreased considerably in rats with CCI (P < 0.05), and in comparison with model group, those of EA group increased markedly (P < 0.05). Compared with sham group, GFAP immunoactivity (mainly in the lamina I-II of the spinal dorsal horn), TNF-alpha mRNA and IL-1beta mRNA expression in the ipsilateral spinal cord on the CCI side in model group increased considerably (P < 0.05), while compared with model group, the expression of GFAP, TNF-alpha mRNA and IL-1beta mRNA in EA group was down-regulated remarkably (P < 0.05).

CONCLUSIONS

EA can effectively suppress CCI-induced up-regulation of expression of spinal GFAP, TNF-alpha mRNA and IL-1beta mRNA, which may contribute to its effect in reducing mechanical allodynia and thermal hyperalgesia in neuropathic pain rats.