全脑缺血再灌注损伤大鼠早期脑皮质超微结构的变化

背景大量研究报道了全脑缺血再灌注损伤模型形态学上的变化,但是,再灌注早期皮质超微结构的变化、特别是血脑屏障的变化报道较少.目的探讨全脑缺血再灌注损伤大鼠早期脑皮质神经元、胶质细胞和血脑屏障的变化,为临床治疗提供可靠的依据.设计随机对照的实验研究.单位北京天坛医院神经外科、麻醉科和电镜室.材料实验于2003-02/2004-02在首都医科大学附属北京神经外科研究所对6只Wistar大鼠进行研究.随机分为2组,缺血再灌注组(3只)和假手术对照组(3只).干预制备大鼠全脑缺血再灌注模型.缺血组于缺血再灌注1 h、假手术组于手术后1 h取脑,利用电镜技术观察皮质超微结构的变化.主要观察指标皮质超微结构变化.结果缺血再灌注早期(1 h)皮质神经细胞发生不同程度的固缩.胶质细胞肿胀,核内染色质溶解,核膜不清.血管周围足突轻度肿胀、与基膜分离.微管有部分溶解.结论再灌注损伤早期皮质神经元、胶质细胞、细胞骨架和血脑屏障即发生变化.提示降低脑水肿、保护血脑屏障等脑保护治疗应越早越好.

Ultrastructural changes of brain cortex in rats at early stage of global ischemia reperfusion injury

BACKGROUND: Quiet a number of researches has reported the morphological changes of global ischemic reperfusion model. However, there are few reports on the ultrastructural changes of cortex in early reperfusion, especially the change of blood brain barrier.OBJECTIVE: To explore the changes of brain cortex neurons, glial cells and blood brain barrier in order to provide reliable evidence for clinical treatment.DESIGN: A randomized and controlled trial.SETTING: Department of Neurosurgery, Departnent of Anesthesia and Electron Microscope Room of Beijing Tiantan Hospital.MATERIALS: The experiment was conducted to 6 Wistar rats in Beijing Neurological Surgery Research Institute of Capital University of Medical Sciences during February 2003 to February 2004. The rats were randomly divided into two groups with one of ischemia-reperfusion group and sham operation group with 3 rats in each group.INTERVENTIONS: To prepare global ischemic reperfusion model of rats. Brain was removed from ischemic group in one hour of reperfusion and from sham operation group one hour after the operation. Electronic microscope technique was used to observe the ultrastructural changes of cortex.MAIN OUTCOME MEASURES: Ultrastructural changes of cortex.RESULTS: The neurons of cortex shrank to certain degree in the early stage of ischemic reperfusion(1 hour) . The glial cells were swollen with dissolved chromosome in nucleus and unclear nuclear membrane. The foot protrusions around blood vessel slightly swelled and separated from basement membrane. Mircro-tubes were partially dissolved.CONCLUSION: In early stage of reperfusion injury, the cortex neurons, glial cells, cellular framework and blood brain barrier already changed which suggested that the protective treatment such as reducing brain edema, protecting blood brain barrier should start as early as possible.