谷氨酰胺合成酶在神经病理性疼痛大鼠脊髓背角的表达

Expression of glutamine synthase in spinal dorsal horn of rats with neuropathic pain

目的:检测谷氨酰胺合成酶(GS)在保留性坐骨神经分支选择性结扎模型(SNI)大鼠脊髓背角的表达与定位,并探讨其在神经病理性疼痛中的作用机制。方法:48只雄性SD大鼠随机分为假手术组(sham组)和SNI组。两组大鼠分别于术前1 d、术后1、3、7和14 d测量机械痛域(PWT),并于术后相应时间点处死,采用Western Blot检测L4-6节段脊髓组织中GS、p-p38、IL-10和TNF-α的表达情况;免疫荧光观察脊髓背角GS的表达与定位情况。结果:与sham组相比,SNI组大鼠PWT于术后1 d开始降低(P<0.05),术后3、7和14 d出现明显差异(P<0.05),模型制备成功。术后3 d和7 d,SNI组大鼠脊髓背角GS、TNF-α和p-p38表达量较sham组明显增高(P<0.05);IL-10表达逐渐下降,在术后7 d和14 d有统计学差异(P<0.05)。结论:GS高表达并主要定位于脊髓背角的星形胶质细胞,GS可能通过p38 MAPK通路参与神经病理性疼痛中的炎症因子的调控。

Objective:To detect the expression and localization of glutamine synthetase(GS)in the spinal dorsal horn of spared nerve injury(SNI)rats,and to explore its mechanism in neuropathic pain.Methods:Forty-eight male SD rats were divided into sham-operate group(sham)and SNI group.The paw withdrawal threshold(PWT)of rats was measured by van Frey filaments.The expression of GS,p-p38,IL-10,and TNF-αin L4~L 6 spinal cord of rats were detected by Western Blot.The expression and localization of GS in spinal dorsal horn of rats were observed by immunofluorescence staining.Results:Compared with sham group,the PWT of rats in SNI group began to decrease at1 day after operation(P>0.05),and there were significant differences at day 3,7,and 14 after operation(P>0.05).The expression of GS,TNF-α,and p-p38 in spinal dorsal horn of rats in SNI group was significantly higher than that in sham group at 3 and 7 days after operation(P>0.05),while the expression of IL-10 decreased gradually(P>0.05).Conclusion:GS is highly expressed and mainly localized in astrocyte of the spinal dorsal horn.GS may participate in the regulation of inflammatory factors in neuropathic pain through p38 MAPK pathway.