Objective To investigate the effect of low sound pressure level infrasound on chemokine-mediated inflammatory response in spinal cord in rats with neuropathic pain. Methods Seventy-two healthy male SD rats were randomly divided into sham operation group (group Sham), neuropathic pain group (group NP) and low sound pressure level infrasound intervention group (group LNP), 24 in each. The sciatic nerve injury models were established. 3 d after the model constructed, the rats in group LNP started to receive low sound pressure level infrasound therapy, 4 h per day, continued for 21 d. 1 d before surgery (T0) and3 dafter surgery (T1), all rats were detected mechanical paw with drawal threshold (MWT). Respectively, after treated for 7d (T2),14 d (T3) and 21d (T4), eight rats were randomly selected from each group and their MWT was measured. The expressions of MCP-1 mRNA, CCR2 mRNA, TNF-α mRNA, IL-1β mRNA, and IL-6 mRNA in spinal cord in rats were detected using quantitative PCR, the expressions of MCP-1 protein and CCR2 protein in spinal cord in rats were detected by using Western blot. Results MWT in groups NP and LNP at T1-T4 was lower than that of group Sham, and that in group LNP at T3-T4 were higher than that of group NP, respectively (P<0.05). Compared with group Sham, the relative expression levels of MCP-1 mRNA, CCR2 mRNA, TNF-α mRNA, IL-1β mRNA, and IL-6 mRNA in spinal cord tissues in groups NP and LNP at T2-T4 were increased (P<0.05); compared with group NP, the relative expression levels of MCP-1 mRNA, CCR2 mRNA, TNF-α mRNA, IL-1β mRNA, and IL-6 mRNA in spinal cord were decreased in group LNP at T3-T4 (P<0.05). Western blot analysis showed that the relative expression levels of MCP-1 protein and CCR2 proteinin spinal cord in groups NP and LNP at T2-T4 were higher than that of group Sham, while relative expression levels of MCP-1 protein and CCR2 protein in spinal cord in group LNP at T3-T4 were lower than that of group NP. Conclusion The low sound pressure level infrasound could effectively reduce neuropathic pain in rats, possibly via inhibiting chemokine-mediated cascade inflammatory reaction. |