钙及钙调蛋白依赖性激酶在神经元缺氧损伤中的作用  

Effects of calcium and calmodulin dependent kinase against hypoxic neuronal injury

作　　者：周晖[1] 孙小妹[1] 罗小丽[1] 毛萌[1] 

机构地区：[1]四川大学华西第二医院儿科,四川成都610041

出　　处：《中国当代儿科杂志》2007年第4期324-326,共3页Chinese Journal of Contemporary Pediatrics

基　　金：国家自然科学基金(项目号:30371489);教育部科学技术研究重点项目(项目号:0133);国家自然科学基金(项目号:30400478)

摘　　要：目的探讨钙及钙调蛋白依赖性激酶(calmodulin dependent kinase,CaMK)在神经元缺氧损伤中的作用及机制。方法体外培养大鼠胚脑皮质神经元,随机分为单纯缺氧组及钙阻滞剂干预组,其中钙阻滞剂干预组采用尼莫地平(nimodipine)、MK-801分别阻断L-VSCC受体、NMDA受体的传导,采用MTT法测定各组神经元缺氧前后细胞活性,用Fluo-4AM荧光探针测定各组细胞内钙离子浓度的变化,Western blot检测CaMKⅡ及CaMKⅣ的表达。结果尼莫地平及MK-801组细胞活性较单纯缺氧的对照组高;尼莫地平可迅速降低缺氧神经元的细胞内钙,MK-801可长时间降低缺氧神经元的细胞内钙。尼莫地平可抑制CaMKⅡ的表达,MK-801对CaMKⅡ的表达无明显影响,但可抑制CaMKⅣ的表达。结论尼莫地平和MK-801可分别通过抑制CaMKⅡ和CaMKⅣ表达实现对缺氧神经元的保护作用。Objective To study the effects of calcium and calmodulin dependent kinase against hypoxic neuronal injury and its possible mechanisms. Methods Embryonic cortical neurons of 17-day pregnant embryo Spragne-Dawley rats were cultured in vitro and the cultured neurons were randomly allocated into different groups that exposed to hypoxia or hypoxia ＋ calcium channel antagonist. Nimodipine and MK-801 were used to block the L-voltage sensitive calcium channel and NMDA receptor respectively before hypoxia. The methyl thiazolyl tetrazolium（MTr） method was used to determine the cell viability. Fluo-4AM, an intracellular calcium indictor, was used to detect the changes of intracellular calcium after hypoxia. The expressions of CaMK Ⅱ and CaMK IV were detected by Western blot. Results The cell viability of the nimodipine or MK-801-treated groups was significantly higher than that of the untreated hypoxia group. The intracellular calcium level of the nimodipine-treated group decreased rapidly after hypoxia. Compared to nimodipine treatment, MK-801 treatment could inhibit hypoxia-induced calcium influx for a longer time. Nimodipine treatment decreased the CaMK Ⅱ expression while MK-801 treatment decreased the CaMK Ⅳ expression. Condusions Nimodipine and MK-801 protect neurons from hypoxic injury possibly by the inhibition of CaMK Ⅱ and CaMK Ⅳ expressions respectively.

关 键 词：神经元 缺氧损伤 钙 钙调蛋白依赖性激酶 大鼠 

分 类 号：R363[医药卫生—病理学]