氙气延迟后处理诱导蛋白激酶B信号通路活化对大鼠脊髓缺血再灌注损伤的保护作用

The Protective Roll of Xenon Delayed Post-conditioning Via AKT Signal Pathway Activation in Spinal Cord Ischemia/Reperfusion Injury in Rats

目的:探讨蛋白激酶B(Akt)信号通路在氙气延迟后处理对大鼠脊髓缺血再灌注损伤中的作用。方法:建立大鼠脊髓缺血再灌注损伤模型。采用随机数表法将实验动物分为7组(n=16):脊髓缺血再灌注组(I/R组)、脊髓缺血再灌注+氙气延迟后处理组(I/R+Xe组)、脊髓缺血再灌注+PI3K/Akt阻断剂组(I/R+wortmannin组)、脊髓缺血再灌注+阻断剂溶剂二甲基亚砜(DMSO)组(I/R+DSMO组)、脊髓缺血再灌注+PI3K/Akt阻断剂+氙气延迟后处理组(I/R+wortmannin+Xe组)、脊髓缺血再灌注+阻断剂溶剂DMSO+氙气延迟后处理组(I/R+DMSO+Xe组)、假手术组(Sham组)。分别于缺血再灌注后6、12、24、48 h观察记录大鼠后肢运动功能,于缺血再灌注后4 h(n=8)和48 h(n=8)行尼氏染色、TUNEL染色检测存活及凋亡指数,行蛋白印迹法(Western blot)测定脊髓组织中p-Akt蛋白表达。结果:与Sham组相比,其余各组大鼠在各检测时点后肢运动功能评分显著降低,脊髓前角运动神经元存活数量显著减少、凋亡数量显著增加,p-Akt水平显著增高(P<0.05)。I/R+Xe组较I/R组大鼠在各检测时点后肢运动功能评分显著增加,脊髓前角运动神经元存活数量显著提高、凋亡数量显著减少,p-Akt水平显著增高(P<0.05)。I/R+wortmannin+Xe组较I/R+Xe组大鼠在各检测时点后肢运动功能评分明显下降,脊髓前角运动神经元存活数量显著减少、凋亡数量显著增加,p-Akt水平显著降低(P<0.05)。结论:氙气延迟后处理通过激活Akt信号通路对大鼠脊髓缺血再灌注损伤起到保护作用。

Objective：Spinal cord ischemia/reperfusion（I/R） injury may lead spinal cord functional impairment and paraplegia,and we want to investigate the protective roll of xenon（Xe） delayed post-conditioning via protein kinase B（Akt） signal pathway activation in spinal cord I/R injury in experimental rats.Methods：A total of 112 male SD rats were divided into 7 groups：1 I/R group,2 I/R＋Xe group,3 I/R＋wortmannin（PI3K-Akt blocker） group,4 I/R＋DMSO（solvent） group,5 I/R＋wortmannin＋Xe group,6 I/R＋DMSO＋Xe group,7 Sham group.n=16 in each group.The excise function in hind legs of rats were observed at 6,12,24,48 hours after treatment;the survival neuron was examined by Nissl staining and TUNEL staining at 4,48 hours after treatment,and the protein expression of p-Akt in spinal cord was measured by Western blot analysis.Results：Compared with Sham group,all other groups showed obviously decreased excise function in hind legsof rats with less spinal motor neurons,more apoptosis and lower protein expression of p-Akt at each time point,P〈0.05.Compared with I/R group,I/R＋Xe group presented increased excise function in hind legs,more spinal motor neurons,less apoptosis and elevated protein expression of p-Akt P 〈0.05.Compared with I/R＋Xe group,I/R＋wortmannin＋Xe group indicated decreased excise function in hind legs,less spinal motor neurons,more apoptosis and inhibited protein expression of p-Akt,P 〈0.05.While protein expression level was similar between I/R group and I/R＋wortmannin＋Xe group,P 〉0.05.Conclusion：Xenon delayed post conditioning may protect spinal cord I/R injury via Akt pathway activation in experimental rats.