新生鼠缺氧缺血性脑损伤脑细胞凋亡的研究

目的　利用大鼠缺氧缺血性脑损伤动物模型 ,观察缺氧缺血性脑损伤后不同时间细胞形态变化及细胞的死亡形式 ,为缺血缺氧性脑病提供实验和理论依据。方法　 7日龄SD大鼠 6 6只 ,随机分为对照组、假手术组和实验组 (缺氧缺血不同时间 ) ,实验组动物采用阻断左侧颈总动脉后置于含 8%O2 的低氧环境中 ,建立缺氧缺血性脑损伤动物模型。用HE、硫堇及TUNEL染色技术在光镜下观察脑组织的病理改变。结果　大鼠缺氧缺血后 3h时脑细胞即有水肿 ,6h时发现有局灶性坏死 ,12、2 4和 48h可发现大量坏死神经细胞 ;在缺氧缺血后 3h细胞凋亡出现 ,之后凋亡细胞数目明显增加。凋亡出现在细胞坏死之前。结论　新生鼠缺氧缺血性脑损伤后 ,细胞死亡有凋亡和坏死两种形式。

Survey of brain cells apoptosis damaged by hepoxia-ischemoc injery in neonatal rats

Objective To observe the pathological changes of brain exposed hypoxia-ischemic brain damage(HIBD) in the different times. The changes of cell configurations and death patterns also be observed, to provided experimental and theoretic foundation for the coming mechanism of hypoxia-ischemic encephalopathy(HIE). Method Sixty-six neonatal SD rats were devided randomly into pseudo-oparative groups , control groups and experimental group. The animal model of hypoxic-ischemic brain damage (HIBD)was established by inhaling the mixed gases of 8%O 2 and 92%N 2 after being ligated left neck common artery(NCA). The pathological changes of brain tissues were observed under light microscopy by HE, sulfur cordierite and TUNEL staining. Result (1)The edema of brain cell appeared in 3h after ligation of NCA and the local necrosis took place in 6h , a large amount of dead nerve cells appeared in the times of 12h,24h and 48h. (2)The apoptosis cells appeared in 3h after hypoxia-ischemic injery and increased prograssively, the apoptosis took place before the necrosis. Conclusion The death of brain cells exposed HIBD were of two types, apoptosis and necrosis.