大鼠颅脑损伤后大脑中动脉形态结构的变化

目的探讨颅脑损伤后大鼠损伤侧和对侧大脑中动脉形态结构及管壁细胞Cx40、Cx43的改变。方法成年SD大鼠45只按随机数字表发随机分为正常组（9只）、假手术组（9只）及损伤组（27只）,损伤组又根据伤后时间分为伤后6 h、24 h、72 h三个亚组（每亚组9只）。利用液压冲击法建立大鼠颅脑损伤模型,通过显微镜和透射电镜观察损伤侧和对侧大脑中动脉形态学改变,免疫组化法检测管壁细胞Cx40、Cx43表达水平改变。结果颅脑损伤后,大鼠损伤侧大脑中动脉随时间进程出现不同程度的内皮细胞形态结构改变、内弹力膜皱缩、平滑肌细胞水肿变形,进而管腔出现不同程度的狭窄甚至闭塞;损伤对侧大脑中动脉也出现形态结构改变,但发生较晚,程度较轻。与对照组相比,损伤组大鼠损伤侧和对侧大脑中动脉血管壁细胞Cx40、Cx43表达均明显增加（P〈0.05）,伤后24 h达高峰。结论颅脑损伤后不仅损伤区域大血管受损,远隔区域大血管亦可见损伤性改变。

Changes in the morphology and levels of vascular wall cells Cx40 and Cx43 expressions of middle cerebral artery after traumatic brain injury in rats

Objective To investigate the changes in the morphology and levels of the vacular wall cells connexin（Cx） 40 and Cx43 expressions of the middle cerebral artery（MCA） after traumatic brain injury（TBI） in order to provide experimental evidence for intracranial vascular injury after TBI.Methods Forty-five adult Sprague-Dawley rats were randomly divided into normal group（n=9）,sham injury group（n=9） and injury group（n=27）, which were redivided into 6, 24 and 72 hours after TBI subgroups of 9 rats each. Brain injury model was established by fluid percussion injury method. The light microscope and transmission electron microscope were used to observe the changes in morphology of both the left and right MCA in all the groups. The levels of MCA walls cells Cx40 and Cx43 expressions were determined by immunohistochemical technique in all the group.Results The lumna of MCA ipsilateral and contralateral to the injury narrowed, the change in the endothelial cell morphology occurred, internal elastic membrane shrank, and the smooth muscle cells swelled edema and deformed after TBI. The levels of Cx40 and of Cx43 expressions in the wall cells of MCA ipsilateral and contralateral to the injury in all the injury groups, which reached the peak 24 hours after TBI, were significantly higher than that in the control group（P〈0.05）.Conclusion The arteries in the injured cerebral area and near the injured cerebral area not only are injured, but also the arteries distal to the injured cerebral area are injured after TBI.