镁对局灶脑缺血神经保护作用的实验研究

目的 :观察MgSO4 、Mg2 + -ATP对局灶脑缺血的治疗作用。方法 :线栓法制备SD大鼠可逆性右侧大脑中动脉缺血模型 (MCAO) ,缺血 2h后再灌流 ,72小时后处死大鼠。观察神经功能缺损评分 ,用图象分析技术测定脑梗死体积 (比 )、脑水肿体积 (比 ) ;并原位标记DNA片断 ,检测TUNEL法染色阳性细胞数 ;测定血清神经元特异性烯醇化酶 (NSE)水平 ;动态观察血清镁和血糖浓度。结果 :MgSO4 组、Mg2 + -ATP组较对照组再灌注后 2小时神经功能缺损评分无差异 ,而 72小时评分有显著差异 (P <0 0 0 1) ,且脑梗死体积 (比 )、脑水肿体积 (比 )、TUNEL阳性细胞数 ,血清NSE水平均低于对照组 (P <0 0 5 ) ;但MgSO4 组、Mg2 + -ATP组两组之间各项指标无显著性差异 (P <0 0 5 )。结论 :镁能减轻局灶脑缺血后脑损伤 ,这种保护作用可能与镁减少迟发性神经元损伤有关 ;Mg2 + -ATP未能加强镁的作用。

The Experimental Study of Neuroprotective Effects of Magnesium on Focal Cerebral Ischemia

Objective:To study the neuroprotective effects of MgSO4 on focal cerebral ischemia. Methods:The middle cerebral artery occlusion(MCAO) models in Sprague-Dawley rats treated with MgSO4 and Mg2+-ATP were performed for 2 hours and reperfusion for 72 hours.The outcomes including:①neurological deficient score after reperfusion 2 hour and 72 hours.②infarct and edema volume evaluated by a computerized image analysis system.③level of serum neuron-specific enolase (NSE).④neuron apoptosis in the infarct border detected by using the terminal deoxynucleotidal transfererase-mediated dUPD-biotin nick end lableling DNA fragments in situ(TULEL) at 72 hours after reperfusion.⑤serum concentration of Mg2+ and blood suger 0.5 hour and 2 hours after ischemia. Results:The neurological score,the infarct volume,edema volume and the level of NSE at 72 hours after reperfusion in the group treated with MgSO4and Mg2+-ATP were significantly improved compared with control group (P<0.05)except neurological score at 2 hours after reperfusion(P>0.05).The number of the TUNEL positive neurons was also significantly lower in the FNZ group than control group(P<0.001).But there is no different outcome between MgSO4 group and Mg2+-ATP group.Conclusion:Magnesium may have neuroprotective effects on focal cerebral ischemia. The mechanism is probably related to the effect inhibiting apoptosis procedure of magnesium.