弥漫性轴突损伤合并局灶性脑挫伤动物模型

目的 :研制弥漫性脑损伤 (DAI)合并局灶性脑挫伤的动物模型。方法 :观察该模型大鼠各种病理生理学改变及大鼠脑各部位肉眼、光镜、电镜下的形态学改变。结果 :①DAI合并脑挫伤组死亡率为 12 % ,假手术组及单纯DAI组无死亡 ;②DAI合并脑挫伤组后意识恢复时间 [平均 ( 5 19± 0 .49)h]较单纯DAI组 [平均 ( 2 75± 0 .16 )h]及假手术组 [平均 ( 2 77± 0 2 0 )h]明显延长 (P <0 .0 1) ;③免疫染色切片显示 ,DAI合并脑挫伤组鼠脑多个部位 (皮层下、胼胝体、脑干 )呈广泛性轴索损伤改变 ;④电镜显示DAI合并脑挫伤组有髓神经纤维节段性变性膨大、轴突内神经微丝排列混乱、髓鞘板层呈松散空泡样变。结论 :提示本动物模型类似于人类脑外伤时常见的弥漫性轴索损伤合并局灶性脑挫伤 ,大鼠伤后出现的原发性持续昏迷与人类此种脑外伤后的临床病理生理接近 ,该模型简易、经济、实用、重复性好

Model of diffuse axonal injury and focal brain injury in rats

Objective: To establish a rather ideal experimental brain injury model in rats, in which diffuse axonal injury(DAI) and focal brain contusion were made concurrently. Methods: The pathophysiological changes were monitored, and the histological changes were observed under naked eye, microscope and electric microscope. Results: ① The mortality in the group suffering from DAI with focal contusion(Group A) was much higher than that in DAI(Group B) and sham group(Group C); ②The time of postinjury primary coma in Group A [(5.19±0.49) h] was longer than that in Group B [(2.75±0.16) h] and Group C [(2.77±0.20) h] significantly(P<0.01); ③ Immunohistological examination showed that the diffuse axonal injury could be seen in several parts of the brain(subcortical, corpus callosum and brainstem) in Group A; ④ We observed in Group A under electric microscope that the axons were swollen and degenerated fragmently, neurofilements ranged disorderly and there was vacuolation. Conclusion: The model is cheap, simple and can be easily repeated. Furthermore it can be used to research the changes of pathophysiology, histology and moleculobiochemistry of head injury in human beings.