脊髓背根神经节河豚毒素不敏感钠通道“再分布”可能导致急性切口痛敏现象

The redistribution of TTX-R sodium channel at DRG may be related to the hyperalgesia of acute incisional pain

目的研究急性切口痛模型中脊髓背根神经节（DRG）河豚毒素不敏感型钠通道（TTX-R）信使核糖核酸（mRNA）表达、通道分布改变，探讨急性切口痛这种复合炎性痛和神经源性疼痛的分子基础，并探讨钠离子通道在其中的可能作用。方法30只SD大鼠随机均分为两组，实验组（A组）：大鼠右足底行1cm长手术切口建立急性痛模型；对照组（B组）：行假手术处理。原位杂交、实时（RT）-PCR监测术前、术后24、48、96h右侧L4～L6 DRG上Nav1．8和Nav1．9 TTX-R钠通道mRNA表达水平、通道分布情况的变化。结果原位杂交和RT-PCR表明两组Nav1．8和Nav1．9的mRNA水平差异无统计学意义，但A组在术后各时点不同直径DRG细胞上存在“再分布”现象。结论DRG细胞TTX-R钠通道“再分布”现象可能在急性切口痛模型痛敏状态中起到一定作用。

Objective To investigate the changes of mRNA and distribute of tetrodotoxinresistant （TTX-R） sodium Channel in dorsal root ganglia （DRG） during the acute incisional pain. Methods Thirty rats were randomly allocated equally into two groups. Group A accepted a 1 cm longitudinal incision on the right hindpaw. Group B was control group. The change of Channel mRNA and distribution at right L4-6 DRG was measured by in-situ hybridization and real-time PCR before operation,at 24,48 and 96 h postoperatively. Results Although there were individual changes of the Nav1. 8 and Nay1.9 mRNA at DRG neurons cells, the changes had no obvious differences compared with those before operation. There were apparent redistribution phenomenons, especially Nav1. 8, at small and large diameter DRG neurons postoperatively. Conclusion The redistributed of TTX-R sodium channel,especially Nav1. 8,may contribute to the hyperalgesia of the acute incisional pain.