镁对脑缺血早期脑组织中谷氨酸及一氧化氮含量的影响

为研究镁在脑缺血早期对神经元保护作用的机制，用电凝法建立大鼠大脑中动脉缺血模型，在造模前给大鼠注射２０ｇ／Ｌ硫酸镁，观察镁对脑组织中谷氨酸（Ｇｌｕ）及一氧化氮（ＮＯ）含量的影响。结果显示，高浓度镁可明显降低脑缺血皮质中Ｇｌｕ、ＮＯ含量，在缺血组Ｇｌｕ、ＮＯ的峰值浓度分别为９．８７、４４．９７ｎｍｏｌ／ｇ，而在加镁组两者浓度分别为７．６８、３３．９２ｎｍｏｌ／ｇ。提示：镁对脑缺血早期神经元的保护作用与其降低脑组织中Ｇｌｕ及ＮＯ含量有关。

Effects of Magnesium Sulfate on Nitric Oxide and Glutamate Contents in Occlusion Cortex after Focal Cerebral Ischemia in Rats

To study the mechanism of protective role of Mg2 on neurons in the early stage of focal cerebral ischemia, the model of focal cerebral ischemia was established by occluding the middle cerebral artary. Before ischemia, 20 g/L magnesium sulfate was injected intravenously into the rat to investigate the effect of Mg2 on nitric oxide (NO) and glutamate (Glu) contents in occlusion cortex. The results demonstrated that high concentration of Mg2 could obviously decrease the contents of NO and Glu in occlusion cortex. In ischemia group, the peak contents of Glu and NO were 987 nmol/g, 4497 nmol/g respectively. In the Mg2 treated group, the peak contents of Glu and NO were 768 nmol/g, 3392 nmol/g respectively. The results suggested that the decerease of Glu and NO contents may contribute to the protective roles of Mg2 in neurons in the early stage of cerebral ischemia.