切口痛大鼠脊髓背角兴奋性突触后膜Neuroliginl表达的变化

Changes in expression of neuroliginl in excitatory postsynaptic membrane of spinal dorsal horn in a rat model of incisional pain

目的评价切口痛大鼠脊髓背角兴奋性突触后膜突触细胞粘附分子Neuroligin1表达的变化。方法清洁级健康成年雄性SD大鼠48只，体重280～320 g，6～8周龄。采用随机数字表法分为2组：对照组（C组，n＝12）和切口痛组（I组，n＝36）。I组制备大鼠右足切口痛模型，于术后3 h（T1）、1 d（T2）和3 d（T3）时随机取12只大鼠行累积疼痛评分（CPS），测定机械缩足反应阈（MWT）。然后处死大鼠取L3-6节段脊髓背角，采用Western blot法检测脊髓背角突触后膜Neuroligin1、突触后膜致密蛋白（PSD-95）、谷氨酸受体1（GluR1）和谷氨酸受体2（GluR2）的表达，采用免疫共沉淀技术检测脊髓背角Neuroligin1和PSD-95的共表达。结果与C组比较，I组T1-3时CPS升高，MWT降低，T1，2时脊髓背角突触后膜Neuroligin1和GluR1表达、T1时Neuroligin1与PSD-95共表达上调（P〈0.05或0.01）。结论大鼠切口痛的形成与维持的机制与脊髓背角突触后膜Neuroligin1调控的信号通路有关。

Objective To evaluate the changes in the expression of neuroligin1 in excitatory postsynaptic membrane of the spinal dorsal horn in a rat model of incisional pain.Methods Forty-eight pathogen-free healthy adult male Sprague-Dawley rats, aged 6-8 weeks, weighing 280-320 g, were divided into control group（group C, n=12）and incisional pain group（group I, n=36）using a random number table.A 1 cm long incision was made in the plantar surface of the right hindpaw in group I. Cumulative pain score（CPS）was assessed and mechanical paw withdrawal threshold to von Frey stimuli was measured at 3 h and 1 and 3 days after operation（T1, 2, 3）. The animals were then sacrificed and their lumbar segments（L3-6）of the spinal cord were removed for detection of the expression of neuroligin1, postsynaptic density-95 protein（PSD-95）, glutamate receptor 1（GluR1）and GluR2 in the postsynaptic membrane of spinal dorsal horn（by Western blot）and co-expression of neuroligin1 with PSD-95 in spinal dorsal horn（by co-immuno-precipitation）.Results Compared with group C, CPS was significantly increased and mechanical paw withdrawal threshold was decreased at T1-3, and the expression of neuroligin1 and GluR1 in the postsynaptic membrane of spinal dorsal horn at T1, 2 and co-expression of neuroligin1 with PSD-95 at T1 were up-regulated in group I（P〈0.01 or 0.05）.Conclusion The development and maintenance of incisional pain is related to the signaling pathway regulated by neuroligin1 in excitatory postsynaptic membrane of the spinal dorsal horn of rats.