缺血后适应对大鼠局灶性脑缺血再灌注后谷氨酸的影响

Effect of ischemic postconditioning on glutamate levels after focal cerebral ischemia reperfusion in rat

目的:研究缺血后适应对大鼠局灶性脑缺血再灌注后谷氨酸(Glu)浓度变化的影响。方法:建立大鼠大脑中动脉阻塞(middle cerebral artery occlusion,MCAO)模型,将36只雄性SD大鼠随机分为假手术(Sham)组、脑缺血再灌注(I/R)组和缺血后适应(I Postcond)组,每组12只。应用高效液相色谱检测缺血脑组织匀浆Glu浓度。结果:局灶脑缺血再灌注6 h后,I Postcond组Glu浓度相较I/R组明显降低(P<0.01),局灶脑缺血再灌注24 h后,I Postcond组Glu浓度较I/R组低,但两者差异亦无显著性(P>0.05)。结论:本研究表明,I Postcond能够减轻MCAO大鼠模型中I/R损伤。细胞间隙Glu清除的加速可能是其重要保护机制之一。

Objective： To investigate the effect of ischemic postconditioning on glutamate after focal cerebral ischemia reperfusion.Methods： The MCAO（middle cerebral artery occlusion） models of rats were made.36 male Sprague-Dawley rats were randomly divided into 3 groups（n=12）： Sham-operate（Sham） group,ischemia/reperfusion（I/R） group and ischemic postconditioning（I Postcond） group.We used high performance liquid chromatography（HPLC） to examine the glutamate concentration of the ischemic brain tissue homogenate.Results：The extracellular concentrations of glutamate were significantly lower in the I Postcond group compared with the I/R group（P〈0.01） 6 hours after reperfusion.The extracellular concentrations of glutamate were lower in the I Postcond group compared with the I/R group 24 hours after reperfusion,but no significant differences between them（P〉0.05）.Conclusion： The present study showed that I Postcond alleviates I/R injury in MCAO rat model.Accelerating the elimination of glutamate in extracellular space might play an important role on this effect.