预缺血抑制脑缺血诱导GluR6巯基亚硝基化机制的研究  

Study of the inhibition of the cerebral ischemia - induced S - nitrosylatiol of GIuR6 by ischemic preconditioning in SD rats

作　　者：王梅[1] 张光毅[1] 

机构地区：[1]徐州医学院生物化学与分子生物学研究中心,江苏省脑病生物信息重点实验室,江苏徐州221002

出　　处：《徐州医学院学报》2011年第3期141-144,共4页Acta Academiae Medicinae Xuzhou

基　　金：国家自然科学基金（30870543）

摘　　要：目的 观察预缺血对SD雄性大鼠全脑缺血/再灌注后海马CA1区锥体细胞的保护作用,并探讨其可能的机制.方法 采用四动脉结扎法构建大鼠预缺血模型和全脑缺血模型,缺血6 min后分别灌注6 h或5天.大鼠随机分为假手术组、缺血/再灌注组、预缺血/再灌注组、预缺血/再灌注溶剂对照组和预缺血/再灌注给药组.预缺血/再灌注给药组腹腔注射5 mg/kg MK801.主要运用SDS-PAGE、免疫印迹和焦油紫染色法等技术检测相关信号蛋白的表达、活化水平及神经元细胞的死亡情况.结果 大鼠缺血/再灌注6 h,预缺血/再灌注组和预缺血/再灌注溶剂对照组的GluR6的巯基亚硝基化水平较缺血/再灌注组明显降低,而预缺血/再灌注给药组较缺血/再灌注组没有明显变化;各组间GluR6的蛋白表达量并没有明显变化.大鼠缺血/再灌注5天后,预缺血/再灌注组和预缺血/再灌注溶剂对照组海马CA1区细胞的存活数量较缺血/再灌注组明显增加,而预缺血/再灌注给药组较缺血/再灌注组没有明显变化.结论 预缺血通过NMDA受体下调大鼠全脑缺血/再灌注诱导的KA受体亚基GluR6的巯基亚硝基化,从而发挥拮抗缺血性脑损伤的作用.Objective To investigate the neuroprotection of ischemia preconditioning on the hippocampal CA1 pyramidal neurons following global cerebral ischemia/reperfusion in SD rat models, and to explore the possible underlying mechanism. Methods Animal models of ischemic preconditioning and global cerebral ischemia was established by the four - vessel occlusion method （4 - VO） for transient brain ischemia （6 min）, followed by reperfusion for 6 h or 5 days. Rats were randomized into 5 groups： sham operation group, ischemia/reperfusion group （ I/R group） , ischemic preconditioning/reperfusion group （P group）, ischemic preconditioning/reperfusion ＋ saline pretreatment control group （ P ＋ saline group） and ischemic preconditioning/reperfusion ＋ MK801 pretreatment group （P ＋ MK801 group）. The rats in the P ＋ MK801 group was given a peritoneal injection of 5 mg/kg MK801. Immunoblot （IB）, SDS -PAGE and cresyl violet staining methods were applied to detect the expression and activation of relevant message proteins, and the death of hipp- ocampal neurons. Results At 6 h after ischemia/reperfusion, S - nitrosylation of GluR6 in P group and P ＋ saline group decreased as compared to I/R group, while no marked change was observed in P ＋ MK801 group in comparison with I/R group; there were no significant variations in the protein expression of GluR6. 5 days after ischemia - reperfusion, the survival of hippocampal CAI pyramidal neurons significantly increased in P group and P ＋ saline group when compared with I/R group, while there was no marked change in P ＋ MK801 group in comparison with I/R group. Conclusion Ischemic preconditioning has neuroprotective effects against ischemia - induced cerebral damage by the downregulation of the global cerebral ischemia/reperfusion - induced S - nitrosylation of KA receptor subunit GluR6 via the NMDA receptor in rat models.

关 键 词：脑缺血/再灌注 预缺血 谷氨酸受体6 NMDA受体 巯基亚硝基化 

分 类 号：R364.12[医药卫生—病理学]