【摘要】 目的　检测谷氨酸兴奋毒损伤时 ,在胞外有 Ca2 +或无 Ca2 + ,或有尼莫地平和 Ca2 +条件下 ,神经细胞内〔Ca2 +〕i的变化。方法　用Fura- 2 / AM体外检测新生大鼠皮层神经细胞胞内游离钙离子浓度的方法。结果　发现谷氨酸兴奋毒可使皮层神经细胞〔Ca2 + 〕i上升并有剂量依赖性 ,胞外无 Ca2 +或加入尼莫地平时神经细胞〔Ca2 +〕i虽也上升 ,但幅度降低 ;三种条件下神经细胞在兴奋毒作用下〔Ca2 +〕i变化各不相同。结论　表明谷氨酸活化神经细胞膜上受体 ,使胞内钙库动员和细胞膜 Ca2 +通道开放 ,导致〔Ca2 +〕i在短时间内总体表现为持续上升。存在兴奋毒损伤过程中有磷脂酶 A2 活化过度参与的信使基础。更多还原

【Abstract】 Objective To investigate the change of the neuron intracellular Ca²⁺ density after excitotoxicity. Methods Fresh cortical neurons were isolated from new-born rats. Before and after t he Glutamic acid excitotoxicity, the intracellular Ca²⁺ density were deter mined by fura-2 fluorometry under different conditions: extracellular Ca²⁺ exist or not exist, or both extracellular Ca²⁺ and nimodipine exist. Results Glutamic acid excitotoxicity significantly increased the neuron intracellular Ca²⁺ density and has a dose-dependent manner. The ef fect was especially obvious under the extracellular Ca²⁺exist condition. Conclusions Our results suggest that Glutamic acid might stimul ate intracellular Ca²⁺ stores and Ca²⁺ channels in the membrane by a ctivating its receptor on the neuronal membrane, so that the intracellular Ca 2+) rise in a short time and phospholipase A2 activation would be involved in the process.更多还原