目的  观察Ⅰ型补体受体(CR1)蛋白在脑淀粉样血管病变中的表达。方法  以APP-PS1转基因小鼠（Tg6799）为动物模型，取小鼠海马及颞叶脑组织，分别采用蛋白质印迹法和酶联免疫吸附试验对脑组织中的CR1蛋白进行定量检测；以CD31作为血管内皮细胞的标志物，用免疫荧光进行CR1和CD31共定位，观察CR1蛋白在血管中的表达变化。以Aβ40作为脑淀粉样血管病变的标志物，进行CR1和Aβ40免疫荧光共染色，观察CR1是否在脑淀粉样血管病变中表达。结果   蛋白质印迹法和酶联免疫吸附试验结果显示CR1蛋白在APP-PS1转基因小鼠中的表达明显高于正常小鼠。免疫荧光检测显示CR1蛋白在APP-PS1转基因小鼠的血管中呈颗粒或团块状分布，且在脑淀粉样血管病变中表达。结论   CR1可能在脑淀粉样血管病变的发病中起到重要的作用。

Objective  To observe the expression of complement receptor 1 (CR1) protein of patients with cerebral amyloid angiopathy (CAA). Methods  APP-PS1 transgenic mice (Tg6799) were used as the animal model of CAA. The hippocampus and temporal cortex tissues of mice were harvested and the CR1 protein was detected by Western blotting and enzyme-linked immune sorbent assay (ELISA). CD31 was regarded as the marker of vascular endothelial cells and co-localization of CR1 and CD31 was performed by immunofluorescence. Changes of the expression of CR1 protein in blood vessels were observed. Aβ40 was regarded as the marker of CAA and immunofluorescence staining of CR1 and Aβ40 was performed by immunofluorescence. The expression of CR1 of Tg6799 mice was observed. Results  The results of Western blotting and ELISA showed that the expression of CR1 protein of APP-PS1 transgenic mice was significantly higher than that of normal mice. The results of immunofluorescence showed that CR1 protein in blood vessels of APP-PS1 transgenic mice was granular or lumpish and Tg6799 mice expressed CR1 protein. Conclusion  CR1 may play an important role in the pathogenesis of CAA.