脑缺血大鼠大脑皮质NMDA受体的早期表达

目的　探讨脑缺血和缺血再灌注早期大脑皮质NMDA受体的变化规律。方法　健康雄性SD大鼠 4 8只 ,随机分为 6组 :假手术对照组、单纯脑缺血 1 5min、2 0min和 30min组及脑缺血 1 5min再灌流 30min和 2 4h组 ;4血管脑缺血动物模型 ;连续冰冻冠状切片观察 ,NR1 免疫组化染色特异性地显著NMDA受体的变化 ,图象分析及计算阳性单位PU值。结果　①单纯脑缺血各组PU值分别为 7 5 5± 1 81、6 91± 2 5 3和 6 0 9± 1 5 0 ,与对照组PU值 9 0 4± 1 5 7相比呈下降趋势 (P≤ 0 0 5 ) ;②再灌流 30min和 2 4h组PU值分别为 5 76± 2 2 4和 4 73± 1 34,与对照组PU值相比明显减少 36 2 9%～ 4 7 6 8% ,有统计学意义(P <0 0 5 ) ;③再灌流 0min、30min和 2 4h组两两比较 ,除 2 4h和 0min组相比NR1 阳性反应物减少有统计学意义 (P <0 0 5 )外 ,其它组别间NMDA受体下降的变化无显著性差异 (P >0 0 5 )。结论　脑缺血和缺血再灌流早期NMDA受体都存在下行调节 ,这种调节可能是一种保护性作用

Immunohistochemical study of NMDA receptor in rats cerebral cortex areas during the early phase cerebral ischemia

Objective To study the change of NMDA receptors during the early phase of cerebral ischemia and ischemic and ischemic reperfusion.Methods 48 male SD rats was randomly divided into 6 groups:sham operated control group,cerebral ischemia 15 min?20 min?30 min,cerebral ischemia 15 min reperfusion 30 min and 24 h groups.The four vessel occlusion(4 vo)ischemic model was performed with the method of Pulsinlli Brierley in this experiment.Brain section was botained by cryostat sectioning.The section were prepared for NR 1 immunohistochemistry staining and was observed by optical microscope.Quantitative analysis was carried out for NR 1 immunoreactive matter and calculated the PU value.Therefore,the change of NMDA receptor was indicated specifically.Results ①The PU values of cerebral cortex in the groups of cerebrai ischemia were separately 7 55±1 81,6 91±2 53 and 6 09±1 50,the NR 1 immunoreactive protein levels tended to decrease in contrast with the PU value(9 04±1 57)of the control group( P ≤0 05);②The PU values of cerebral cortex in the groups of reperfusion 30 min the 24 h were separately 5 76±2 24 and 4 73±1 34,and the NR 1 immunoreactive protein levels significantly decreased 36 29%～47 68% in contrast with that in the control group( P <0 05);③The PU values were compared between reperfusion 0 min?30 min and 24 h groups.The reperfusion 24 h group were lower significantly than reperfusion 0 min group( P <0 05),but there were no significant reductions between other groups( P >0 05).Conclusion The present results demonstrate that the decrease of NMDA receptors might be one of the mechanism for protection against ischemia in the early phase of cerebral ischemia and ischemic reperfusion.