缺氧缺血对新生乳鼠脑组织的损伤作用

Pathological Study of Perinatal Hypoxic-Ischemic Brain Damage in Rats

目的观察缺氧缺血对新生乳鼠脑组织病理学改变。方法70只健康7日龄Wistar新生乳鼠,结扎后离断左侧颈总动脉,置于37.0℃、8%O2+92%N2缺氧箱2h后取出,分别于7d、14d、30d处死取脑,HE染色、免疫组化、透射电镜观察脑组织病理学改变。结果HE染色:7d后结扎侧脑室周围可见神经细胞排列紊乱,部分神经细胞变性坏死,细胞肿胀,炎细胞浸润;30d结扎侧脑室周围多个囊腔形成;免疫组化染色:结扎侧脑室周围髓鞘碱性蛋白(MBP)阳性细胞数随时间延长逐渐减少,而胶质纤维酸性蛋白(GFAP)阳性细胞数随时间延长逐渐增多,部分染色包绕囊腔,局部染色聚集;电镜:7d可见细胞形态尚规则、水肿,双层结构不清,部分线粒体空泡样变,细胞核染色质浓缩;30d可见细胞形态不规则,部分核膜破损,核内容物外溢。结论新生乳鼠一侧颈总动脉结扎结合缺氧的方法可造成结扎侧脑室周围细胞水肿,变性坏死,软化灶形成。

Objective To investigate the pathological changes in neonatal rats after hypoxic ischemic insults. Methods 70 normal 7 day old Wistar rats were divided into two groups randomly： hypoxic ischemic and control group. The left carotid arteries were per manently ligated and cut in hypoxic-ischemic group. All the animals were exposed hypoxia （92% N2 , 8% O2） for 2 h in a constant thermal environment. All the brain tissues were observed with electronmicroscopy, HE and immunohistochemistry stain 7 d, 14 d and 30 d after injury. Results HE stain showed that neurocytes arranged disorder in the side of the carotid ligation 7 d after injury. Some degenerated neurocytes, swelled cells and inflammatory cell infiltration also visualized. Many capsular spaces were observed in the side of the carotid ligation 30 d after injury. Immunohistochemistry staining showed Myelin basic protein （MBP） positive neuro cytes gradually decreased, and glia fibrillary acidic protein （GFAP） positive neurocytes gradually inreased in the periventricular zone with the time lapsed. It was observed that the neurocytes were edema, many mitochondrias were vacuolus, caryotins were condensed under transmission electron microscope 7 d after operation. The morphocytology of the neurocytes were irregulated obviously, part of nuclear membranes were broken down with the content leakaged 30 d after operation. Conclusion The characteristics of periven-tricular leukomalacia can be developed after hypoxic ischemic insults in the rats.