新生大鼠脑缺氧缺血损伤模型的建立

Establishment of an experimental model of hypoxic-ischemic damage in neonatal rats

目的 按Rice方法建立新生大鼠脑缺氧缺血损伤(HIBD)模型。方法 7d龄SD新生大鼠 6 2只 ,随机分为正常对照组 (n =14 )、假手术组 (n =14 )及HIBD模型组 (n =34)。HIBD模型组大鼠行左侧颈总动脉永久性结扎 ,2h后置于 37℃恒温水浴的 1L有机玻璃缺氧舱中 ,输入氧浓度为8%± 0 1%的氮氧混合气体持续缺氧 2h ,观察缺氧缺血后2 4h内神经行为变化及 2 4、4 8、72h脑组织病理改变 ,并用干湿法测定 2 4h脑含水量。结果 HIBD模型组大鼠神经行为异常发生率为 94 12 % ,正常对照组和假手术组未发生神经行为异常。HIBD模型组左侧脑组织出现明显的病理改变 ,HE染色可见神经元损伤和神经胶质细胞增生 ;正常对照组和假手术组脑组织未见异常。HIBD模型组左脑含水量较右脑、正常对照组和假手术组显著增加 (P <0 0 0 1)。结论 应用Rice方法建立的新生大鼠HIBD模型稳定性良好 ,其病理变化有一定的规律性 ,该模型的建立对于研究新生儿HIBD具有重要意义。

Objective To establish an experimental model of hypoxic-ischemic brain damage (HIBD) in neonatal rats established by Rice. Methods Sixty-two 7-day old Sprague-Dawley (SD) neonatal rats were randomized into the normal control group (n=14),the sham-operation group (n=14) and the HIBD group (n=34). HIBD models were established as follows: the left common carotid artery of each pup was permanently ligated. After 2 hours, the rat pups were placed in 1L airtight jars and exposed to a continuous flow of oxygen-nitrogen mixture in which the oxygen concentration was 8%±0.1% for 2 hours. The jars were partially submerged in 37℃ water bath to maintain a constant thermal environment.The neural behavior in 24 h after hypoxic-ischemia was evaluated. the brains were sampled out at 24, 48, 72 h after hypoxic-ischemia and the pathologic changes were observed. The water content in brain tissues at 24 h was measured as well. Results ①The abnormity incidence of the neural behavior in the HIBD group was 94.12%.②In the HIBD group,the pathological changes of the left brain were obvious. HE staining showed the neuron damage and the proliferation of neuroglial cells;there was no abnomity in the other two groups.③The water content of left brain increased significantly in HIBD group compared with the normal control group and sham-operation group (P<0.001).Conclusion The model of HIBD is stable and the pathologic changes of the brain tissues are with certain regularity. The method established by Rice for studying HIBD deserves more wide use.