缺氧预处理对脑缺血大鼠海马超微结构的影响

The effects of hypoxic preconditioning on hippocampal ultrastructure in rats with brain ischemia

目的观察缺氧预处理对脑缺血大鼠海马CA1区神经细胞和星形胶质细胞超微结构的影响。方法将60只雄性Wistar大鼠随机分为3组:(1)窒息心脏停搏组(ACA组,n=20),大鼠遭受窒息性心脏停搏1min后复苏;(2)脑缺氧预处理+窒息心脏停搏组(HP+ACA组,n=20),在窒息性心脏停搏前24 h给予大鼠1min的脑缺氧预处理4次,每次间隔5 min;(3)脑缺氧预处理组(HP组,n=20),只给予4次脑缺氧预处理。观察各组大鼠死亡率和复苏后神经功能评分(NDS),72 h后取海马CA1区组织置电子显微镜下观察神经细胞和星形胶质细胞超微结构改变情况。结果与ACA组相比,HP+ACA组死亡率显著降低(5% vs.30%,P<0.01),NDS明显改善(P<0.05),神经细胞和星形胶质细胞超微结构改变明显减轻。结论脑缺氧预处理可明显减轻脑缺血大鼠海马CA1区神经细胞和星形胶质细胞缺血性形态学改变。

Objective To observe the effects of hypoxic preconditioning （HP） on hippocampal ultrastructure after brain ischemia in rats. Methods Sixty male Wistar rats were randomly assigned to three groups： （1） The ACA group were subjected to 1 min of asphyxiaI cardiac arrest （ACA） and then resuscitated; （2） The HP＋ACA group were pretreated with 4 times of 1 rain hypoxic preconditioning 24 h before ACA; （3） The HP group were treated with 4 times of 1 min HP, there were 20 rats in each group. Mortality and neurodeficit score （NDS） were assessed. Hippocampal CA1 region were removed 72 h after resuscitation and observed with electron microscopy. Results Compared with the ACA group, rats in the HP＋ ACA group showed significant decreased mortality （50% vs. 30%, P〈0.01） and improved NDS （P〈0.05） . The morphologic impairment of neurons and astrocytes were significantly less severe in HP＋ACA group than that in ACA group. Conclusions HP could alleviate the hippoeampal ultrastructural damage after brain ischemia in rats.