实验性家兔动脉粥样硬化形成中细胞间黏附分子-1表达的变化

Changes of intercellular cell adhesion molecule-1 in rabbit atherogenesis

目的观察细胞间黏附分子（ICAM）-1在动脉粥样硬化（AS）形成中的作用，并试图探讨循环可溶性ICAM-1（sICAM-1）与局部ICAM-1表达的剂量关系。方法雄性新西兰纯种白兔56只，随机分为对照组24只（喂饲普通饲料）和模型组32只（予高脂饮食喂养）；于试验的2、4、6、8周末随机处死每组兔6～8只，取血行血脂及sICAM-1检测，取胸主动脉用免疫组化法检测ICAM-1表达。结果对照组血脂在实验前后无明显变化，而模型组血浆胆固醇、甘油三酯、低密度脂蛋白在2周末时较实验前及对照组即均已明显升高，随实验进展有继续升高趋势。本实验血清中未检测到sICAM-1。免疫组化染色显示，对照组兔血管壁仅内皮细胞ICAM-1呈弱阳性表达，而模型组随高脂饮食时间延长内皮细胞表达增强，且斑块内和中膜平滑肌表达亦逐渐增强、表达范围逐渐增大。结论ICAM-1参与了AS的形成和发展，血清sICAM-1浓度与血管局部ICAM-1间可能为一种高剂量相关关系。

Objedive To investigate the role of intercellular cell adhesion molecule- 1（ICAM- 1） in rabbit atherogenesis and the dose- dependent association between local expressions of ICAM - 1 and circulation soluble ICAM - 1 （slCAM - 1 ）. Methods A total of 56 male New white rabbits weighing 1.8- 2.4 kg were randomly assigned to control group（group C,fed with whole-grain common diet, n = 24） and atherosclerosis group（group AS,fed with an atherngenic diet, n = 32）.By the end of second,4th,6th,and 8th weeks of the study,6- 8 rabbits of each group were sacrificed and blood was drawn from vein for analysis of cholesterol and serum sICAM- 1,meanwhile aortas were harvested.The arches of thoracic aortas were stained with hematoxylin - eosin.The pathological changes were then observed under light microscope and aortic ICAM- 1 was studied by immunohistochemical technique.Results Levels of blood cholesterol in group C did not have obvious changes during the test. with group C,levels of blood cholesterol including total cholesterol,TG,and LDL in group AS remarkably increased by the end of second week and further increased with the test progression. The expression of serum soluble ICAM - 1 was not detected by technique using a double primary sandwich ELISA.Lecal expressions of aortic ICAM- 1 detected by immunohistochemistrial staining were weakly positive only in endothelium in group C while more prominent in endothelium and gradually exparded to AS lesion and middle surface muscle cells when continually fed with high cholesterol diet in group AS.Conclusions The expressions of aortic ICAM- 1 are aggravating during the progression of AS,showing that it takes part in the initial and development of AS. The relationship between local expressions of ICAM- 1 and circulation sICAM - 1 might be highly dose dependent.