兴奋性氨基酸受体对大鼠坐骨神经切断后脊髓神经细胞的影响

Influence of AMPA receptor on spinal nerve cells in rats with sciatic nerve transection

目的通过建立神经再生室模型观察α-氨基-3-羧基-5-甲基-4-异口恶唑丙酸(AMPA)受体对大鼠坐骨神经损伤后L3～6脊髓神经细胞凋亡及凋亡相关蛋白表达的影响。方法雄性SD大鼠,随机分为4组:AMPA组,6-氰-7-硝基喹喔啉-2,3-二酮(CNQX)组,细胞内液组以及正常对照组,前3组手术切断右侧坐骨神经并用硅胶管套接,分别向套管内注入AMPA,CNQX,细胞内液5μl,术后1,2,4周应用TUNEL及免疫组化技术检测L3～6脊髓神经细胞凋亡及凋亡相关蛋白Bcl-2、Bax表达的情况。结果(1)不同时间段凋亡细胞检测结果:CNQX组犤(4.9±0.8)%,(14.1±2.6)%,(4.4±0.6)%犦,明显低于细胞内液组犤(9.4±1.7)%,(19.3±1.7)%,(6.6±0.6)%犦,AMPA组犤(14.4±1.6)%,(25.7±1.3)%,(9.1±0.9)%犦则高于细胞内液组,t=3.7～5.7,P均<0.01。(2)不同时间段Bcl-2的表达:CNQX组犤(13.1±2.3)%,(22.9±2.4)%,(10.3±2.7)%犦高于细胞内液组犤(9.0±1.9)%,(17.4±1.2)%,(7.7±1.7)%犦,相反AMPA组犤(5.0±0.9)%,(11.8±2.8)%,(4.5±1.1)%犦则低于细胞内液组,t=1.8～4.4,P<0.05～0.01。(3)不同时间段Bax的表达:CNQX组犤(4.2±0.9)%,(12.5±1.3)%,(3.9±0.5)%犦低于细胞内液组犤(7.9±3.0)%,(16.8±1.5)%,(6.9±1.6)%犦。而AMPA组犤(11.8±2.0)%,(21.8±1.8)%,(10.5?

Aim To observe the effects of AMPA receptor on the apoptosis and apoptosis related protein expression in the spinal cord after sciatic nerve transection in rat.Methods Fifty male Sprague Dawely rats were randomly divided into 4 groups(AMPA group, CNQX group, intracellular fluid group,normal control group),6 mm Right Sideness sciatic nerve defects were made and bridged with silicon tubes in the former 3 groups. 5 μl 10 μmol/LAMPA,10 μmol/L CNQX and intracellular fluid were injected into the silicon tubes of the experimental groups respectively.The apoptosis and expression of apoptosis related protein Bcl 2,Bax in the spinal cord of L3-L6 level were determined with TUNEL and immunohistochemical method at 1,2 and 4 weeks after sciatic nerve transection. Results (1)The number of apoptosis cells at 1,2,4 week in intracelluar fluid group [(9.4±1.7)%,(19.3±1.7)%,(6.6±0.6)%] was more than that in CNQX group[(4.9±0.8)%,(14.1±2.6)%,(4.4±0.6)%] respectively,and less than that in AMPA group[(14.4±1.6)%,(25.7±1.3)%,(9.1±0.9)%] respectively(t=3.7-5.7,P< 0.01).(2)The Bcl 2 expressions at 1,2,4 weeks in intracelluor fluid group[(9.0±1.9)%,(17.4±1.2)%,(7.7±1.7)%] were higher than those in AMPA group[(5.0±0.9)%,(11.8±2.8)%,(4.5±1.1)%] respectively,and lower than those in CNOX group[(13.1±2.3)%,(22.9±2.4)%,(10.3±2.7)%]respectively(t=1.8-4.4,P< 0.05-0.01).(3)Expression of Bax at 1,2,4 weeks in intracelluar fluid group[(7.9±3.0)%,(16.8±1.5)%,(6.9±1.6)%] were higher than those in CNQX[(4.2±0.9)%,(12.5±1.3)%,(3.9±0.5)%] respectively,and lower than those in AMPA group[(11.8±2.0)%,(21.8±1.8)%,(10.5±1.8)%]respectively(t=2.4-4.8,P< 0.05-0.01). Conclusion AMPA receptor antagonist preserves the neuron of spinal cord after sciatic nerve transection ,but its agitation AMPA destroys this process.