阿尔茨海默氏病大鼠淀粉样变性脑血管病的病理学变化

Pathological study of cerebral amyloid angiopathy in rat models of Alzheimer's disease

目的在建立实验性大鼠阿尔茨海默氏病动物模型基础上探讨淀粉样变性脑血管病变的脑组织病理变化特点。方法在立体定向仪引导下向大鼠双侧海马内注射Aβ1-42纤维,建立阿尔茨海默氏病动物模型,应用水迷宫试验评价大鼠高级认知功能情况,应用HE染色、刚果红染色以及α-actin、Aβ双重标记免疫荧光染色观察淀粉样蛋白在大鼠脑内沉积与淀粉样变性脑血管病变的动态变化情况。结果模型组与假手术对照组相比逃避潜伏期时间和平台探索次数均有显著性差异。HE染色可见模型组大鼠海马区颗粒细胞减少,细胞变性,胶质细胞增生,海马内小血管壁变性。刚果红染色可见Aβ纤维逐渐沉积在小血管壁,管壁增厚,小血管狭窄或闭塞;免疫荧光染色可见模型组脑组织内Aβ纤维逐渐向小动脉迁移。结论淀粉样变性脑血管病变是阿尔茨海默氏病的主要病理变化。

Objective To examine cerebral pathologies in cerebral amyloid angiopathy in a rat model of Alzheimer＇s disease. Methods Rat models of Alzheimer＇s disease was established by stereotactic Aβ1-42 fiber injection in the bilateral hippocampus. The cognitive function of the rats was evaluated with water maze test. HE staining, Congo red staining and double-labeling indirect immunofluorescence were used to examine the dynamic distribution of Aβ fiber deposit in the brain. Results The model rats showed significant differences from the control rats in the escape latency and the times of crossing platform in waster maze test. HE staining revealed a decreased number and degeneration of the granular cells with increased glial cells in the model rats. Congo Red staining showed that the Aβ fiber was deposited gradually in the small vessels in the brain parenchyma to cause thickening, stenosis or occlusion of the small vessels. Immunofluorescence staining detected Aβ fiber migration from the parenchyma to the walls of the small arteries in the rat models. Conclusion Cerebral amyloid angiopathy is a major pathological feature in Alzheimer＇s disease.