Roles Of AQP1 And AQP2 In Spinal Cord Of Rats With Neuropathic Pain

Objective:To study roles of AQP1 and AQP2 in Spinal Cord of Rats with Neuropathic Pain.Method:Twenty-five healthy male SD rats were randomly divided into five groups with five rats in each group. Basic mechanical and thermal pain threshold were tested during the first day, the third day, the sixth day, the nineth day, the sixteenth days when the study began. CCI model was established in fifteen rats. Five rats were selected as sham-operation group (group E). Five rats were selected as control group (group D). CCI rats were killed on the sixth day (group A), the nineth (group B) and the sixteenth (groupsC,D,E) when the study began. Lumbar spinal cords of rats in all groups were dissected out. The localization of AQP1 and AQP2 were demonstrated by immuo-histochemical assay. The levels of mRNA expression of AQP1 and AQP2 were detected by relative real-time fluorescent quantitative PCR assay.Result:1. Hyperalgesia in CCI rats:Mechanical hyperalgensis emerged on the third day when the study was begun. Thermal hyperalgensis emerged on the sixth day when the study began (P< 0.05).2. Localization and expression of AQP1 and AQP2:In Lumbar segment of spinal cords of rats in each group, AQP1 and AQP2 positive particles were presented in neuronal cytoplasm widespreadly,especially were concentrated in the left spinal cord dorsal.The expression of AQP1 and AQP2 of CCI goups were more intensive than the others.3. Expression of AQP1 mRNA and AQP2 mRNA in CCI rats:The mean AQP1 and AQP2 mRNA content in the CCI groups were higher than those in the control group and the sham group (P< 0.05). The mRNA expression of AQP1 in A,B,Cgroups were 1.688,4.876,5.806 times than that of the control group, respectively. The mRNA expression of AQP2 in A,B,C, groups were 1.037,3.359,4.682 times than that of the control group, respectively. No significant difference was observed in the mean AQP1 and AQP2 mRNA content between the group D and group E(P>0.05).Conclusion:The mRNA and the protein expression of AQP1 and AQP2 were increased in CCI rats. AQP1 and AQP2 signal pathway may play roles in the pathgenesis of neuropathic pain in rats induced by chronic constriction injury to the sciatic nerve, respectively.