L5前根切断大鼠模型中背根神经节P2X3受体表达

目的：探讨L5前根切断（L5VRT）大鼠神经病理性疼痛模型背根神经节（DRG）P2X，受体表达。方法：雄性SD大鼠30只，随机分为5组（n=6），A组（UVRT术后3d）、B组（L5VRT术后7d）、C组（L5VRT术后14d）、D组（UVRT术后21d）模型组和E组（假手术组），E组仅行半椎板切除术暴露左侧脊髓，分别在各自的时间点灌注取材L5背根神经节，用免疫荧光染色方法观察P2X3受体表达的变化。结果：（1）L5前根切断手术后，大鼠从次日开始即能产生双足明显的机械痛敏，与E组相比差异有统计学意义（P〈0．05），这种痛敏情况持续至少4周；（2）免疫荧光染色发现B组、C组及D组模型组同侧15DRG的P2X3受体的表达明显增加（P〈0．01），B组、C组及D组模型组对侧L5DRG的P2X3受体的表达与E组相比变化不明显（P〉0．05）；A组模型组的双侧L5DRG的P2X3受体的表达与E组相比无明显变化（P〉0．05）。结论：（1）L5前根切断疼痛模型能产生双足明显的机械痛敏；（2）该模型背根神经节P2X3受体的表达变化可能参与其机械痛敏的机制。

P2X3 Receptor Expression in Dorsal Root Ganglion in Rats with Lumbar 5 Ventral Root Transection

Objective： To observe the P2X3 receptor expression in lumbar 5 dorsal root ganglion（ L5 DRG）with lumbar 5 ventral root transection （L5 VRT）. Methods： Thirty male Sprague-Dawley rats were randomly divided into 5 groups, group A 3 days after L5 VRT, group B 7 days, group C 14 days, group D 21 days and group E of sham operation, whose left spine cords were exposed by hemilaminectomy. Rats in each group were respectively perfused with paraformaldehyde and materials were taken from L5 dosal root ganglions and the changes of expression of P2X3 receptor were observed with immtmofluorescence staining. Results ： （ 1 ） Compared with the control group, rats after operation could generate bilateral mechanical allodynia which could persist for at least 4 weeks （ P 〈 0. 05 ） ; （2） The expressions of the receptors of P2X3 in ipsilateral L5 DRG of 7 days, 14 days and 21 days after transection were significantly increased compared with the control group （P 〈0.01 ）, but in contralateral I5 DRG of 7 days, 14 days and 21 days were not changed and neither in bilateral L5 DRG in group A （P 〉0.05）. Conclusions： （ 1 ） The rats with L5 VRT can generate bilateral mechanical allodynia; （2） The changes of expression of P2X3 receptor in DRG of rats with L5 VRT might play a role in the mechanism of mechanical allodynia.