褪黑素对小鼠缺血再灌注脑损伤后海马CA3区神经元的保护作用

Protection of melatonin to CA3 hippocampus neurons of mice on cerebral ischemia-reperfusion injury

目的:观察褪黑素(melatonin,MT)对缺血再灌注脑损伤小鼠学习记忆能力的影响,探讨MT对缺血再灌注脑损伤的神经保护作用。方法:将60只健康小鼠随机分为对照组,模型7d组和治疗7d组。模型组采用双侧颈总动脉夹闭法建立小鼠缺血再灌注脑损伤,治疗7d组分别于处死前3d腹腔注射MT(20mg/kg,3次/d),对照组同时给予等量生理盐水。各组小鼠于处死前3d采用Y-型电迷宫检测小鼠学习记忆能力,行为检测完毕后行脑组织SOD、NO、MDA及脑组织含水量检测;电镜下观察海马CA3区神经元超微结构变化。结果:与模型组相比,治疗7d组小鼠的学习记忆能力明显改善(P<0.05);治疗7d组SOD含量显著升高,NO、MDA含量明显下降;电镜下,较非治疗组海马神经元的损伤明显改善。结论:褪黑素可以明显改善缺血再灌注脑损伤小鼠的学习记忆能力,不同程度的减少或减轻神经元的损害,说明其具有神经保护作用。

Objective To observe the effect on learning and memory abilities of mice on ischemia- reperfusion brain injury,and discuss the protection of Melatonin （MT） on hippocampus neurons of mice after cerebral ischemia-reperfusion injury. Methods 60 healthy mouse were randomly assigned to control group, model group and model treatment group. Model group were adopted by the method of bilateral carotid artery occlusion, the treatment group were injected MT （20 rag. kg-1 three times daily） by intraperitoneal injection, the control group was given equivalence physiological saline simuhaneously. Each group were detected the abilities of learning and memory by Y-type maze three days before sacrificed. Then SOD, NO, MDA and the water content of brain tissues were detected and the change of hippocampus CA3 neurons ultra-structural was observed by electron microscopy. Results Compared with the control group, the ability in learning and memory of treatment group was obviously improved （P 〈 0.05）. Biochemical detection, the content of SOD in treatment group was obviously increased （P 〈 0.05）,while the contents of NO,MDA were sensibly decreased（P 〈 0.05）. By electron microscope,observation the injury of hippocampus neurons in treatment group has been greatly in proved than the non-treated groups. Conclusions MT could significantly improve the mice abilities of learning and memory on ischemia-reperfusion brain injury. And MT might have the neuroprotection effect.