脊髓 GAT-1在大鼠背根节慢性压迫神经病理性疼痛中的作用

目的]探讨脊髓γ-氨基丁酸转运体-1（GAT-1）在大鼠慢性背根神经节压迫（CCD）神经病理性疼痛中的作用。方法]选择雄性SD大鼠72只，随机分为假手术组（A组，n＝24）、CCD组（B组，n ＝24）、鞘内NO-711＋CCD组（ C组，n ＝24），三组再按不同时段分为6个亚组（ n ＝4），分别于给药前（T0）、给药后1 h （T1）、4 h（T2）、8 h（T3）、16 h（T4）、24 h（T5）时间点处死大鼠取脊髓腰段进行GAT-1蛋白Western Blot实验。结果]与假手术组相比，B组T0、T1、T2、T3、T4、T5时间点的GAT-1蛋白含量明显增加（ P ＜0．01），鞘内注射生理盐水后，B组的GAT-1蛋白含量无明显改变（ P ＞0．05）；与B组和T0相比，鞘内注射20μg NO-711后T1、T2、T3，C组的GAT-1蛋白含量显著降低（ P ＜0．01），鞘内给药后T4，GAT-1蛋白含量逐渐回升，与B组同一时间点比GAT-1蛋白含量仍明显降低（ P ＜0．05），至给药后 T5 GAT-1蛋白含量回升到正常水平（ P ＞0．05）。结论]CCD模型大鼠脊髓 GAT-1蛋白表达水平上调，GAT 抑制剂 NO-711能明显抑制CCD模型大鼠脊髓GA T-1蛋白表达水平的上调，但是不能抑制GA T-1蛋白基础表达水平。大鼠脊髓背角GA T-1蛋白表达水平的改变与大鼠CCD神经病理性疼痛的机制可能密切相关。

Role of Spinal GAT-1 in Neuropathic Pain Caused by Chronic Compression of Dorsal Root Gan-glion in Rats

Objective] To explore the role of gamma-aminobutyric acid tranporter-1（GAT-1） in neuro-pathic pain caused by chronic compression of dorsal root ganglion（CCD） in rats .Methods]A total of 72 male SD rats were randomly divided into sham group（group A ,n=24） ,CCD group（group B ,n=24） and intrathe-cal NO-711＋CCD group（group C ,n =24） .According to different time ,three groups were divided into six sub-groups（ n=4） .All rats were sacrificed before administration （T0 ） ,1h（T1 ） ,4h（T2 ） ,8h（T3 ） ,16h（T4 ） and 24h（T5 ） after administration .Lumbar spinal cord of rats was collected for Western Blot test of GAT-1 protein .Results] Compared with sham group ,GAT-1 protein in group B at T0 ,T1 ,T2 ,T3 ,T4 and T5 were obviously increased（ P＆lt;0 .01） .After intrathecal injection of normal saline ,GAT-1 protein in group B had no obvious change（ P＆gt;0 .05） .Compared with group B and T0 ,GAT-1 protein in group C at T1 ,T2 and T3 after intrathecal injection with 20 μg NO-711 were markedly decreased （ P ＆lt;0 .01） .GAT-1 protein was gradually increased at T4 after intrathecal administration .Compared with group B ,GAT-1 protein in group C was still obviously decreased at the same time point（ P ＆lt;0 .05） .GAT-1 protein returned to the normal level until T5 after administration（ P＆gt;0 .05） .Conclusion] The expression levels of GAT-1 protein in rat model with CCD are increased .GAT inhibitor NO-711 can obviously inhibit the up-regulation of GAT-1 protein in spine cord of rat model with CCD ,but not inhibit the basic expression level of GAT-1 .The change of GAT-1 protein of spi-nal dorsal horn in rats may be closely correlated with the mechanism of nruropathic pain in rats with CCD .