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目的 探讨缺血预处理脑保护效应，以及神经细胞凋亡与缺血性脑损害的关系。方法 家兔１５只，随机分为３ 组，对照组（Ａ组，ｎ＝ ５），缺血组（Ｂ组，ｎ＝ ５），缺血预处理组（Ｃ组，ｎ＝ ５）。Ａ组只做手术操作，Ｂ组采用二血管夹闭（双侧颈总动脉夹闭，ＭＡＰ＜ ４０ｍ ｍ Ｈｇ）全脑缺血１０ 分钟，Ｃ组在缺血前增加缺血预处理２分钟再灌注３０ 分钟。对比观察缺血后３ 天海马ＣＡ１ 区神经元密度和缺血细胞数，同时使用ＴＵＮＥＬ原位标记法，检测缺血３天后海马区的凋亡细胞。结果 （１）Ｃ组神经元密度与Ａ 组相比差异无显著性，与Ｂ组相比神经元密度显著增加（Ｐ＜ ０．０５）；（２）Ｃ组缺血细胞数较Ｂ组显著降低（Ｐ＜ ０．０１），与Ａ组相比差异无显著性，缺血预处理对海马ＣＡｌ区内、中、外段分别起到８８％ 、８４％ 、７６％ 的保护作用；（３）ＴＵＮＥＬ法显示Ｂ组短暂脑缺血后迟发性神经元死亡中发现神经细胞凋亡，而Ａ组未发现。结论 （１）缺血预处理后３０ 分钟确能对再次缺血发挥脑保护作用；（２）脑缺血可能促进神经细胞凋亡。
Objective To investigate the protective effect of ischemic preconditioning on cerebral ischemia and the relationship between neuronal apoptosis and ischemic brain damage. Methods Fifteen rabbits were randomly divided into 3 groups: control group (group A, n = 5), ischemic group (group B, n = 5) and ischemic preconditioning group (group C, n = 5). Group A was operated only in two groups. Group B received occlusion of the common carotid artery (bilateral common carotid artery occlusion, MAP <40 m Hg) for 10 min after ischemia. Group C received ischemic preconditioning for 2 min before ischemia Perfusion for 30 minutes. The neuronal density and number of ischemic cells in hippocampal CA1 area were observed and compared 3 days after ischemia, and apoptotic cells in hippocampus were detected by TUNEL in situ 3 days after ischemia. Results (1) There was no significant difference in density of neurons between group C and group A (P <0.05). (2) Compared with group B, the number of neurons in group C was significantly higher than that of group B (P <0.01). Compared with group A, there was no significant difference in ischemic preconditioning, and ischemic preconditioning could protect 88%, 84% and 76% ) TUNEL method showed that neuronal apoptosis was found in the delayed neuronal death in group B after transient ischemic attack, but not in group A. Conclusion (1) Ischemia preconditioning can exert cerebral protective effect on ischemic preconditioning for 30 minutes. (2) Cerebral ischemia may promote neuronal apoptosis.