背根神经节中GAT-1表达上调在神经病理性痛 发生发展中的作用

THE ROLE OF THE UPREGULATION OF GABA TRANSPORTER 1 IN THE INJURED DRG IN THE ETIOLOGY ANG DEVELOPMENT OF NEUROPATHIC PAIN

摘要:

摘要 目的：探讨背根神经节 GABA 转运体GAT-1的改变在神经病理性痛发生发展中的作用。方法：制备大鼠坐骨神经慢性压迫损伤(CCI)模型。选取60只雌性SD大鼠，随机分成4组: 对照组（Sham）﹑神经病理性痛模型组（CCI）﹑神经病理痛模型+生理盐水组（CCI+NS）﹑神经病理痛模型+GAT-1抑制剂NO-711组 (CCI+NO-711) , 每组15只。CCI组和 Sham组术后第3、7、14天处死取材，行免疫荧光和Western blot测定两组大鼠背根神经节GAT-1蛋白表达的变化；CCI+NS组和CCI+NO-711组在CCI手术当天和术后第7天，分别于L5 DRG局部注射生理盐水（10 μl）和GAT-1抑制剂NO-711（10 μg/μl，10 μl），记录注射前后CCI大鼠机械缩足阈值(MWT)和热缩爪潜伏期(TWL)的变化以及背根神经节内p-ERK 及脊髓背角内c-Fos的表达。结果：与Sham组相比，CCI组动物术后第3、7、14天L4﹑L5 DRG中GAT-1表达明显增加（P <0.05）；CCI手术当天L5 DRG局部给药后,相比CCI+NS组，CCI+NO-711组动物TWL和MWT升高，并持续至术后第5天（P <0.05）； CCI术后第7天局部给药后，CCI+NO-711组动物TWL和MWT升高，并持续至给药后48 h（P <0.05），背根神经节p-ERK 及脊髓背角c-Fos的表达降低（P <0.05）。结论: 神经损伤后背根神经节内GAT-1的表达明显升高，在神经病理性痛发生发展中起着重要作用。

Abstract:

Abstract Objective: To investigate the expression of GAT-1 in dorsal root ganglion after neuropathic pain. Methods: Female SD rats were used to make chronic constriction injury (CCI) model. Sixty female SD rats were randomly divided into four groups: control group (Sham), neuropathic pain model group(CCI), neuropathic pain model with normal saline group (CCI+NS), neuropathic pain model with GAT-1 inhibitor NO-711 group (CCI+NO-711), fifteen rats per group .On the 3rd 、7rd 、14rd day after operation, the specimens were sacrificed, Western blot and immunofluorescence were used to measure the expression of GAT-1 protein in L4-L5 DRG of Sham group and CCI group . On the day of CCI operation and the 7rd day after operation, NO-711 (10 μg/μl，10 μl ) was injected into the CCI+NO-711 group by local injection of L5 DRG while normal saline (10 μl) was injected into the CCI+NS group respectively. To record the changes of mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) and the expression of p-ERK in DRG and c-Fos in spinal dorsal horn of CCI rats before and after injection. Results: Compared with the Sham group, the expression of GAT-1 protein in L4-L5 DRG was significantly increased in the CCI group on the 3rd 、7rd 、14rd day after operation(P <0. 05). After local L5 DRG injection on the day of CCI operation, compared with the CCI+NS group, the TWL and MWT in the CCI+NO-711 group were raised and lasted until the 5th day after operation （P <0.05）. After local administration of CCI on the 7rd day, the levels of TWL and MWT in the CCI+ NO-711 group were significantly increased , and the effects maintain for 48 hours (P <0. 05)，and the low expression of p-ERK in DRG and c-Fos in spinal dorsal horn were detected（P <0.05）. Conclusion The overexpression of GAT-1 in DRG played an important role in the occurrence and development of neuropathic pain.