小鼠空肠黏膜微血管内皮细胞糖萼的透射电镜观察

Transmission electron microscopic observation of microvascular endothelial glycocalyx in mouse jejunal mucosa

目的建立可靠的小肠黏膜微血管内皮糖萼显示方法,为探讨其生物学功能提供基础。方法取小鼠6只,分为对照组和心脏灌注组,每组3只。对小鼠行乙醚吸入麻醉,心脏灌注组使用梯度阿尔新蓝溶液心脏灌注固定后取空肠组织,对照组直接取空肠组织,然后按照常规方法对其黏膜层制备超薄切片,透射电镜观察。结果透射电镜观察显示,心脏灌注组小鼠肠黏膜微血管内皮细胞膜表面有明显的糖萼结构,呈不连续型和连续型两种形态,不连续性糖萼厚度为50～100nm,连续型糖萼厚度为20～30nm;而对照组未能观察到明显的糖萼结构。结论常规透射电镜样品处理方法,不能显示肠黏膜微血管内皮细胞的糖萼,而心脏灌注阿尔新蓝溶液进行前固定,能够较好地保存该结构,是一种较为可靠的研究方法。

Objective This study aimed to establish a reliable displaying method of the endothelial glycocalyx in small intestinal mucosal microvessels, and to provide a foundation for further studies on its functions. Methods Six mice were divided into a control group and a cardiac perfusion group, three mice each. The mice were anesthetized by inhalation of ether. The jejunum from the cardiac perfusion group was sampled after they were fixed by cardiac perfusion with gradient alcian blue solution and the jejunum from control group was directly sampled. The jejunal mucosa was prepared as ultrathin sections according to the routine method for transmission electron microscopic （TEM） analysis. Results By TEM, the endothelial glycocalyx was shown in jejunal mucosal microvessels of cardiac perfusion group mice, which had two forms, the continued and the discontinued. The continued glycocalyx was 20-30 nm thick, and the discontinued was 50-100 nm. However, the glycocalyx was not found in the control group. Conclusion The endothelial glycocalyx in jejunal mucosal mirovessels is not observaed by TEM in the samples prepared with the traditional method. The cardiac perfusion fixation with alcian blue solution could better preserves the glycocalyx for TEM analysis, and is a reliable method for its study.