大鼠蛛网膜下腔出血后早期脑损伤模型的建立

A model of early brain injury after subarachnoid hemorrhage in rats

目的建立一种微创、重复性好的大鼠蛛网膜下腔出血后早期脑损伤动物模型。方法采用视交叉前池注血法建立蛛网膜下腔出血(SAH)后早期脑损伤(EBI)动物模型。在脑立体定位仪引导下将导管插入视交叉前池,注入300μl自体动脉血建立SAH后EBI模型。进行神经功能学评分,采用激光多普勒血流量仪(LDF)测定局部脑血流量(rCBF),解剖观察前循环周围血液分布情况,应用透射电子显微镜观察海马区神经细胞超微结构变化。结果大部分大鼠在SAH后有神经行为学异常,48 h后逐渐恢复正常。SAH后不同时间点的rCBF均低于对照组。模型组大鼠颅脑解剖发现前循环蛛网膜下腔有大量的血液和血凝块。透射电子显微镜观察:与对照组比较,SAH组神经细胞线粒体和内质网肿胀,核染色质凝聚、趋边。结论此动物模型稳定可靠,重复性高,适合进行临床前循环动脉瘤性蛛网膜下腔出血后早期脑损伤病理生理研究。

Objective To establish a simple and reproducible animal model of early brain injury after subarachnoid hemorrhage in rats. Methods The early brain injury （EBI） model after subarachnoid hemorrhage （SAIl） was induced by stereotactic insertion of a cannula through an artificial hole into the prechiasmatic cistern and injection of 300μl autologus arterial blood. A neurobehavioral evaluation was performed at 24 h and 48 h after SAH. Regional cerebral blood flow （rCBF） was assessed by laser Doppler flowmetry （LDF）. Ultrastructural changes of neuronal cells in hippocampal tissues were observed under transmission electron microscopy. Blood volume and distribution of the subarachnoid space were recorded. Results In model group, lot of blood and blood clot were found in the anterior circulation in subarachnoid space of rat brain. Compared with controls, LDF was obviously decreased in cerebral blood flow （CBF） compared with baseline in control group following SAH （P 〈0.05）. Neurobehavioral disorders were observed in most rats at 24 h after SAH and got recovery at 48 h. Swelling of mitochondrion and endoplasmic reticulum of neuronal cells and condensation of the cytoplasm and peripheral nuclear chromatiu were observed in SAH group under transmission electron microscope. Conclusion The new model is reliable and reproducible which is appropriate for the study on the pathophysiological mechanism of early brain injury of aneurismal SAH in the anterior circulation.