摘要目的 观察大鼠局灶性脑缺血后皮质运动区和海马星形胶质细胞的变化。方法 雄性SD大鼠144只，按随机数字法分成正常组、假手术组和手术组，每组48只。手术组用大脑中动脉电凝术(MCAO)建立局灶性脑缺血模型；假手术组的操作步骤和手术组相同，只是不将暴露的大脑中动脉凝闭；正常组不做任何处理。应用免疫组化检测正常组、假手术组以及手术组术后1、2、3、5、7、14、28、56 d皮质运动区和海马星形胶质细胞神经胶质酸性蛋白(GFAP)表达的变化。结果与正常组和假手术组比较，手术组大鼠缺血侧和健侧MCAO术后皮质运动区GFAP阳性细胞计数术后第1天明显降低，第3天开始升高，缺血侧和健侧分别于术后第7天、第5天升至最高(85.6±3.3、75.3±2.9)，随后逐渐下降并均在术后第14天出现第2个低谷，其后又开始逐渐上升接近正常。与正常组和假手术组比较，手术组海马CA1区GFAP阳性细胞计数缺血侧和健侧自术后第1天即开始升高，术后第7天升至最高( 106.5±3.6、108.4±3.0)，其后进入平台期；CA2区、CA3区缺血侧和健侧术后第3天开始明显升高，CA2区缺血及健侧最高值则分别出现在术后第5天(106.9±4.4)、第7天(107.5±3.8)；CA3区为第5天(130.9±3.7)、第5天(129.2±4.0)，术后第14天开始下降，但仍然高于正常组和假手术组。结论 大鼠局灶性脑缺血后，不同脑区星形胶质细胞的表达随时间变化的模式不同，在皮质运动区存在两谷一峰的现象，在海马表达逐渐增强，并维持在一个较高的水平，这种差别可能与不同脑区神经的可塑性有关。

abstractsObjective To observe the astrocyte changes over time in motor cortex and hippocampus of rat brain tissue after focal cerebral ischemia. Methods A total of 144 male SD rates were randomized into the normal group, sham-operatod group and operated group (n=48 each). The operated group received middle cerebral artery electrocoagulation (MCAO) for modeling of focal cerebral ischemia. The same procedure except for MCAO was given to the sham-operated group, while the control group did not undergo any treatment. On days 1, 2, 3, 5, 7, 14, 28 and 56 post-operation, the three groups were determined for expression of glial fibrillary acidic protein (GFAP) in astrocytes of the motor cortex and hippocampus.Results Compared with the control group and sham-operated group, the post-MCAO GFAP-positive cell count at cortical motor area of ischemia and uninjured sides in the operated group was remarkably reduced on day 1, then started to increase on day 3 and a peak was reached on days 7 (isehemia side, 85.6±3.3) and 5 (uninjured side, 75.3±2.9). Thereafter, the count gradually declined to a second trough on day 14 before slowly returning normal. Compared with the control group and sham-operated group, the post-MCAO GFAPpositive cell count in hippocampal CA1 area of ischemia and uninjured sides in the operated group started to increase and a peak was reached on day 7 (ischemia side, 106.5±3.6; uninjured side, 108.4±3.0), and then remained plateaued; the cell counts in hippocampal CA2 and CA3 areas of ischemia and uninjured sides started to increase on day 3 and a peak was reached on days 5 (ischemia side CA2, 106.9±4.4; ischemia side CA3, 130.9±3.7; uninjured side CA3, 129.2±4.0) and day 7 (uninjured side CA2, 107.5±3.8), then started to decline on day 14 but remained at higher levels as compared with the other two groups.Conclusions The post-MCAO expression of GFAP in astrocytes of different brain areas presents varied changes over time, with two troughs and one peak at cortical motor area, and gradual increase to a higher level at hippocampal areas. Such difference may be associated with varied plasticity of brain areas.