亚低温对大鼠脑缺血再灌注损伤后热休克蛋白70及胶质纤维酸性蛋白表达的影响

目的观察亚低温对大鼠脑缺血再灌注损伤后热休克蛋白70(HSP70)及胶质纤维酸性蛋白(GFAP)表达的影响。方法将雄性Wistar大鼠30只分为假手术组、常温组和亚低温组。制作右侧大脑中动脉阻塞(MCAO)模型,观察缺血2h再灌注48h后各组大鼠脑组织学改变和HSP70及GFAP的表达。结果常温组大鼠脑皮质下神经元严重坏死,亚低温组皮质下神经元坏死严重程度明显较常温组轻,假手术组未见神经元坏死。常温组大鼠脑组织GFAP和HSP70阳性细胞较多,假手术组、亚低温组GFAP和HSP70阳性细胞少于常温组,假手术组偶见HSP70阳性细胞;图像分析显示,常温组大鼠脑组织GFAP、HSP70表达的平均光密度较假手术组和亚低温组明显增高(均P<0.01)。结论亚低温能减轻大鼠脑缺血再灌注损伤,降低脑组织HSP70及GFAP蛋白的表达。

Effects of mild hypothermia on heat shock protein 70 and glial fibrillary acidic protein expression after cerebral ischemia and reperfusion in rats

Objective To observe the effects of mild hypothermia on heat shock protein 70 (HSP70) and glial fibrillary acidic protein (GFAP) expression in cerebral tissue after cerebral ischemia and reperfusion. Methods 30 male Wistar rats were randomly divided into sham-operated group, normal temperature group and mild hypothermia group. The model of focal cerebral ischemia was made by middle cerebral artery occlusion (MCAO) method. After 2 h of MCAO following 48 h of reperfusion, HSP70 and GFAP positive neurons were detected by immunohistochemistry technique in ischemic regions of rats. Results Many necrotic neurons were appeared in normal temperature group and no necrotic neurons in sham-operated group. Fewer necrotic neurons were fond in mild hypothermia group than in normal temperature group. The positive cells of HSP70 and GFAP in sham-operated group and mild hypothermia group were less than normal temperature group. Image analysis revealed that the average optical density of HSP70 and GFAP in sham-operated group and mild hypothermia group was significantly lower than in normal temperature group (all P<0.01).Conclusion Mild hypothermia therapy may inhibit the expression of HSP70 and GFAP after cerebral ischemia and reperfusion injury in rats.