液压脑损伤后大鼠脑血管钝性损伤的研究

发布时间：2018-10-20 17:16

【摘要】：目的：本实验通过建立大鼠侧位液压脑损伤模型，研究液压脑损伤后损伤侧和非损伤侧大血管形态和生理功能改变及微血管损伤与脑水肿的关系，为颅脑创伤后损伤侧和非损伤侧脑血管改变的研究提供实验依据。方法： 1、成年健康雄性SD大鼠45只，采用完全随机法分为正常对照组、假手术组、实验组，实验组又分为液压脑损伤后6h、24h及72h组，每组9只。利用改良的侧位液压损伤装置建立大鼠颅脑损伤模型。应用光镜、透射电镜观察大鼠损伤侧和非损伤侧大脑中动脉主干形态学改变，应用免疫组化法检测不同时间点大鼠损伤侧和非损伤侧大脑中动脉缝隙连接蛋白40（connexin40, Cx40）；缝隙连接蛋白43(connexin43, Cx43)表达的改变。 2、成年健康雄性SD大鼠30只，，采用完全随机法分为正常组、假手术组、实验组，其中实验组分为6h、24h、72h组，每组6只，利用液压冲击法建立大鼠颅脑损伤模型，显微镜观察损伤侧损伤区域和非损伤侧相应区域脑皮质微血管改变情况，CD34标记血管内皮细胞(Endothelial Cell, EC)，采用微血管计数法来检测微血管密度(Microvesseldensity, MVD)改变，干湿重法检测脑组织含水量的变化。结果： 1、液压脑损伤后损伤侧和非损伤侧大脑中动脉均有不同程度损伤，主要表现为血管管腔缩小，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。损伤后72h电镜下可见损伤侧内弹力膜断裂，部分平滑肌细胞核固缩，异染色质增多，非损伤侧改变较轻微；与假手术组相比，实验组大鼠损伤侧和损伤侧大脑中动脉血管壁细胞Cx40、Cx43表达增加(P0.05)，24h达蛋白表达达高峰，尤以损伤侧增加明显。 2、液压脑损伤后大鼠两侧脑皮质微血管均有不同程度皱缩、扭曲，血管周围间隙增宽，损伤后24h和72h组可见微血管内有血栓形成；与假手术组相比脑皮质微血管计数明显降低(P0.05)，以损伤侧为重；实验组损伤侧和非损伤侧脑皮质含水量升高，与假手术组相比差异有统计学意义(P0.05)；脑皮质微血管计数与脑组织含水量呈负相关（r=㧟0.76, P0.01）。结论： 1、液压脑损伤后损伤侧因直接受外力作用，大脑中动脉血管结构改变，管壁内皮细胞出现凋亡表现，非损伤侧则出现内皮细胞变性脱落，平滑肌细胞水肿等改变；同时损伤侧和非损伤侧管壁细胞Cx40和Cx43表达均增加。提示创伤性脑损伤后力线作用方向和非力线作用方向均存在颅内大血管结构和生理功能改变。 2、液压脑损伤后损伤侧和非损伤侧脑皮质微血管扭曲变形，部分血管内可见血栓形成，同时两侧脑组织微血管内皮细胞密度均减低，其降低程度与脑水肿程度吻合。提示创伤性脑损伤后不仅外力直接作用方向微血管有损伤，远隔部位亦可见损伤性改变，脑皮质微血管密度降低是创伤性脑水肿的病理基础。
[Abstract]:Objective: to study the changes of the morphology and physiological function of large vessels and the relationship between microvascular injury and brain edema in the injured side and non-injured side by establishing the model of lateral fluid brain injury in rats. To provide experimental basis for the study of cerebral vascular changes in the injured and non-injured sides after craniocerebral trauma. Methods: 1. Forty-five adult healthy male SD rats were randomly divided into normal control group, sham operation group and experimental group, 9 rats in each group. The model of craniocerebral injury in rats was established by using an improved lateral hydraulic injury device. The morphological changes of the middle cerebral artery trunk in the injured and non-injured sides were observed by light microscope and transmission electron microscope. The gap junction protein 40 (connexin40, Cx40) of the middle cerebral artery at different time points was detected by immunohistochemical method. Changes of gap junction protein 43 (connexin43, Cx43) expression. 2Thirty adult healthy male SD rats were randomly divided into normal group, sham operation group and experimental group. The experimental group was divided into 6 groups with 6 rats in each group. A rat model of craniocerebral injury was established by hydraulic shock. The changes of cerebral cortical microvessels in the injured and uninjured regions were observed under microscope. CD34 labeled vascular endothelial cells (Endothelial Cell, EC),) were used to detect the changes of microvessel density (Microvesseldensity, MVD) by microvessel count. The changes of water content in brain tissue were measured by wet and dry weight method. Results: 1. The middle cerebral artery of the injured side and the non-injured side were damaged to different degrees after fluid pressure brain injury. The main manifestations were the reduction of vascular lumen, the change of endothelial cell morphology, the contraction of internal elastic membrane, and the edema and deformation of smooth muscle cells. Under electron microscope 72 hours after injury, the inner elastic membrane was broken, some smooth muscle nuclei were pyknosis, heterochromatin was increased, and the change of non-injured side was slight. In the experimental group, the expression of Cx40,Cx43 was increased in the injured side and the injured side of the middle cerebral artery (P0.05), and reached the peak at 24 hours, especially in the injured side. Compared with the sham-operated group, the cerebral cortex microvessel count was significantly decreased (P0.05), especially in the injured side. The cortical water content in the experimental group was significantly higher than that in the sham-operated group (P0.05); the cerebral cortex microvessel count was negatively correlated with the brain tissue water content (r = 0.76, P 0.01). Conclusion: 1. The injured side was directly affected by external force, the vascular structure of the middle cerebral artery changed, the endothelial cells of the wall showed apoptosis, and the non-injured side showed degeneration and shedding of endothelial cells. The expressions of Cx40 and Cx43 were increased in both injured and uninjured wall cells. It is suggested that there are changes in the structure and physiological function of intracranial macrovessels after traumatic brain injury. 2. The cerebral cortical microvessels in the injured and non-injured sides are distorted and deformed after fluid pressure brain injury. Thrombosis was seen in some of the blood vessels, and the density of microvascular endothelial cells in both brain tissues was decreased, which coincided with the degree of cerebral edema. It is suggested that not only the direct action of external force has microvascular injury after traumatic brain injury, but also the damage can be seen in the distant area. The decrease of cerebral cortex microvessel density is the pathological basis of traumatic brain edema.
【学位授予单位】：石河子大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R651.15

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