NMDA受体和非NMDA受体在脊神经节损伤介导痛觉过敏中的作用

The role of NMDA and non-NMDA receptors in the hyperalgesia evoked by DRG inflammatory injury

目的研究脊髓背角NMDA受体或/和non-NMDA受体在背根神经节(DRG)炎性损伤所介导的伤侧肢体痛觉过敏中的作用。方法健康家兔42只。实验分为:Ⅰ组(AP-5);Ⅱ组(CNQX);Ⅲ(0.9%生理盐水)。测定用药前后动物神经行为和脊髓背角Glu和Asp含量变化。结果NMDA受体拮抗剂AP-5蛛网膜下腔注射后,机械性刺激缩腿反应强度阈值(MT)值显著高于用药前(P<0.05)。非NM-DA受体拮抗剂CNQX推注后热辐射刺激缩腿反应潜伏期(TL)值显著增高(P<0.05)。脊髓背侧部分氨基酸的浓度有一定变化,如AP-5注射后,脊髓背侧Asp含量(4.48±0.47);CNQX注射后为(4.98±0.41),均明显高于术前水平(2.38±0.13)(P<0.05)。结论DRG炎性损伤后NMDA受体和non-NM-DA受体的激活,在伤侧肢体痛觉过敏的形成和维持中具有重要作用。

ObjectiveTo study the changes of excitatory amino acids (Glu, Asp) contents in the dorsal horn of spinal cord (SDH)and the role of NMDAr and non-NMDAr in the hyperalgesia evoked by DRG inflammatory injury.MethodsThe forty-two health rabbits were divided into:Ⅰgroup(AP-5);Ⅱgroup(CNQX) andⅢ(0.9% Saline). The changes of the behaviors and the Glu, Asp content in the SDH were examined.ResultsThe obviously increase of MT value using the NMDAr antagonist AP-5 ( P <0.05).The greatly decreased of TL value using the non-NMDAr antagonist CNQX ( P <0.05). ConclusionsThe results showed that the increase of Glu, Asp release and the NMDAr and non-NMDAr (AMPAr) activation induced by DRG inflammatory injury played an important role in promoting and maintaining hyperalgesia. But meanwhile the non-NMDAr induced thermal hyperalgesia mainly, but the NMDAr could produce both thermal and mechanical hyperalgesia. After intrathecal administration of NMDAr antagonist AP-5 and non-NMDAr antagonist CNQX, the hyperalgesia following DRG inflammatory injury could be inhibited or attenuated effectively.