硫酸镁对脑缺血再灌注大鼠脑组织Bcl-2表达的影响及神经保护作用

目的探讨硫酸镁对脑缺血再灌注大鼠脑组织抗凋亡蛋白Bcl-2表达的影响及脑保护作用。方法将32只大鼠随机分为缺血组(n=15)、硫酸镁组(n=15)和正常对照组(n=2)。采用改良的Pulsinelli法建立脑缺血再灌注大鼠模型;制模后分别给予缺血组和硫酸镁组大鼠腹腔注射生理盐水(1.5 ml/d)及硫酸镁(90 mg/kg.d)。缺血再灌注第1、3、7 d分别观察各组大鼠海马CA1区病理学改变和Bcl-2的表达水平。结果正常对照组大鼠海马CA1区神经细胞数量多,排列整齐。缺血再灌注1 d时,缺血组及硫酸镁组大鼠海马CA1区神经元均未见明显死亡;3 d时,缺血组海马CA1区神经元可见少量死亡,残存神经细胞呈较严重缺血性改变,硫酸镁组海马CA1区神经元无明显死亡;7 d时,缺血组海马CA1区神经元大部分死亡,伴有小胶质细胞增生,硫酸镁组仅见部分神经元死亡。与缺血组相比,硫酸镁组神经元受损程度较轻,坏死区较小。硫酸镁组缺血再灌注各时间点大鼠Bcl-2阳性细胞较缺血组均明显增加(均P<0.05)。结论硫酸镁能上调脑组织Bcl-2的表达,对缺血再灌注大鼠的脑组织有明显的保护作用。

Influnce and neuroprotective effect of magnesium sulfate on expression of brain tissue Bcl-2 in rats with cerebral ischemia reperfusion

Objective To investigate the influnce and neuroprotective effect of magnesium sulfate on expression of brain tissue anti-apoptosis protein Bcl-2 in rats with cerebral ischemia reperfusion.Method Thirty-two rats were divived into ischemia group(n=15),magnesium sulfate group(n=15) and normal control group(n=2).The rats model of brain ischemia reperfusion were establelished by Pulsinelli’s method.At 1,3,7 d after the model establelished,the normal saline(1.5 ml/d) and magnesium sulfate(90 mg/kg·d) were given by peritoneal injection to ischemia group and magnesium sulfate group respectively.The pathological changes and the expression of Bcl-2 were observed at 1,3,7 d after ischemia reperfusion.Results There were many neurons in hippocampus CA1 region and regular arrangement in normal control group.At 1 d after ischemia reperfusion,the neurons in ischemia group and magnesium sulfate group had no significant deaths.At 3 d,there were a few apoptotic neurons in hippocampus CA1 region in ischemia group,and the residual neurons had seriously ischemic change;the neurons in magnesium sulfate group had no significant deaths.At 7 d,most neurons of hippocampus CA1 region in ischemia group were dead,and accompanied with microglias proliferation;in magnesium sulfate group,there were only part of neurons in hippocampus CA1 region were dead.Compared with ischemia group,the degree of neuronal injuries was milder in magnesium sulfate group;the zone of necrosis was smaller.Bcl-2 positive cells in magnesium sulfate group at each time point after ischemia reperfusion were significantly increase than ischemia group(all P<0.05).Conclusion Magnesium sulfate can up-regulated the expression of Bcl-2 in brain tissue,and has neuroprotective effect after cerebral ischemia reperfusion.