| Objective: To observe the therapeutic effects of 1,8-cineole in rats with neuropathic pain.To investigate the effects and mechanisms that mediated by P2X3 receptors in dorsal root ganglion.Methods: 1.The chronic constiction injury(CCI)rats were used as the neuropathic pain model.2.The rats were randomly assigned into five groups:sham group(Sham);chronic constriction injury group(CCI);CCI rats with dimethysulfo-xide control group(CCI+DMSO);CCI rats treated with low dose 1,8-cineole group(CCI+50mg/kg);CCI rats treated with high dose 1,8-cineole group(CCI+100mg/kg).3.We assessed mechanical withdrawal threshold(MWT)and thermal withdrawal latency(TWL)in the rat models 7thand 14 thdays after surgery.4.We examined P2X3 receptors mRNA change in L4–5 dorsal root ganglia using in situ hybridization techniques and reverse transcription-polymerase chain reaction(qRT-PCR)7th and14 thdays after surgery.5.We examined P2X3 receptors protein change in L4–5 dorsal root ganglion using immunohistochemistry and western-blot 7th and 14 th days after surgery.Results: 1.CCI showed lower MWT and TWL than Sham 7th and 14 th days after surgery(P<0.05),CCI+50mg/kg and CCI+100mg/kg showed higher MWT and TWL than Sham(P<0.05),there was no significant difference between CCI+DMSO and CCI(P>0.05),while CCI+100mg/kg showed higher MWT and TWL than CCI+50mg/kg(P < 0.05).2.After 7th and 14 th days of surgery,the in situ hybridization and qRT-PCR result of P2X3 receptors mRNA expression in L4–5dorsal root ganglion indicate that: CCI was higher than Sham(P<0.05),CCI+50mg/kg and CCI+100mg/kg were lower than CCI(P<0.05),CCI+DMSO showed no significant difference with CCI(P>0.05),while CCI+100mg/kg was lower than CCI+50mg/kg(P<0.05).3.After 7th and 14 th days of surgery,the immunohistoc-hemistry and western-blot results of P2X3 receptors protein expression in L4–5 dorsal root ganglion indicate that: CCI was higher than Sham(P<0.05),CCI+50mg/kg and CCI+100mg/kg were lower than CCI(P<0.05),CCI+DMSO showed no significantdifference with CCI(P>0.05),while CCI+100mg/kg was lower than CCI+50mg/kg.Conclusions: 1,8-cineole can suppress the neuropathic pain mediated by P2X3 receptors in the dorsal root ganglion. |
