RESUMO
Objective To investigate the effect of low sound pressure level infrasound on che-mokine-mediated inflammatory response in spinal cord in rats with neuropathic pain.Methods Seven-ty-two healthy male SD rats were randomly divided into sham operation group (group Sham),neuro-pathic 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 )and 3 d after surgery (T1 ),all rats were detected me-chanical paw withdrawal threshold (MWT).Respectively,after treated for 7 d (T2 ),14 d (T3 )and 21 d (T4 ),eight rats were randomly selected from each group and their MWT was measured.The ex-pressions of MCP-1 mRNA,CCR2 mRNA,TNF-αmRNA,IL-1βmRNA,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-αmRNA,IL-1βmRNA,and IL-6 mRNA in spinal cord tis-sues in groups NP and LNP at T2-T4 were increased (P <0.05);compared with group NP,the rela-tive expression levels of MCP-1 mRNA,CCR2 mRNA,TNF-αmRNA,IL-1βmRNA,and IL-6 mR-NA in spinal cord were decreased in group LNP at T3-T4 (P <0.05 ).Western blot analysis showedthat 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 proteinin 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.