局部亚低温联合硫酸镁对局灶性脑缺血大鼠的保护作用

Protective Effect of Focal Mild Hypothermia Combined with MgSO_4 on the Rats with Focal Cerebral Ischemia

目的:探讨联合应用局部亚低温(32-35℃)及硫酸镁对局灶性脑缺血大鼠的保护作用及其可能机制。方法:通过线栓法建立大鼠大脑中动脉阻塞(MCAO)模型,将40只雄性Wistar大鼠随机分为假手术组、常温组、亚低温组、硫酸镁组、亚低温+硫酸镁组,每组8例,采用Longa神经功能评分、TTC染色、TUNEL技术,检测和比较各组脑缺血后大鼠的神经功能、脑梗死体积、凋亡细胞数。结果:与常温组相比,亚低温组与亚低温+硫酸镁组的梗死体积、神经功能评分、凋亡细胞数均明显降低,差异有显著意义(P<0.05);而与亚低温组相比,亚低温+硫酸镁组局灶脑缺血大鼠的脑梗死体积、神经功能评分、凋亡细胞数均显著减少,差异有显著意义(P<0.05)。结论:与单独应用亚低温相比,局部亚低温与硫酸镁联合应用,对局灶性脑缺血大鼠可发挥更有效的脑保护作用,其机制可能与抑制脑缺血后凋亡有关。

Objective： To investigate the protective effect of focal mild hypothermia combined with MgSO4 on the rats with focal cerebral ischemia and its possible mechanism. Methods： The middle cerebral artery occlusion（MCAO） models of rat were achieved by an intraluminal filament. Forty male aduit Wistar rats were randomly divided into sham-operated group, normothermia ischemia group, MgSO4 group, mild hypothermia group and mild hypothermia＋ MgSO4 group （each group n=8）. The neurological function, infarct volumes, apoptotic cell numbers in the ischemic cortex were assessed by Longa neurological scores, TTC staining and TUNEL. Results： Compared with the normothermia group, the neurological scores, infarct volumes and apoptotic cell numbers markedly decreased in hypothermia group and hypothermia＋MgSO4 group （P〈0.05）. Compared with mild hypothermia group, the neurological scores, infarct volumes and apoptotic cell numbers markedly decreased in hypothermia＋MgSO4 group （P〈0.05）. Conclusion： Focal mild hypothermia combined with MgSO4 was more effective in the protection of rats with focal cerebral ischemia than mild hypothermia, which was partly due to the decrease ofapoptosis.