大鼠动脉粥样硬化不同阶段的血管紧张素变化

Changes of angiotensin1at different stages of atherosclerosis in rats

目的?探讨组织和血浆血管紧张素 (angiotensin ,Ang )与动脉粥样硬化(atherosclerosis,AS)的关系。方法: 40只健康雄性Wistar大鼠随机分为4组(每组10只):正常对照组、高脂组、维生素D负荷组、内皮损伤组,分别以普通饲料、 高脂饲料、高脂饲料+维生素D负荷、高脂饲料+维生素D负荷+内膜球囊损伤术处理,复制大鼠AS形成3个阶段(高脂血 症、纤维增生性动脉硬化、较成熟AS病变斑块形成)模型。利用计算机图像分析系统测定大鼠胸主动脉内(中)膜厚度,采用放 射免疫分析法测定各组大鼠胸主动脉组织和血浆Ang 水平。结果:与正常对照组相比,维生素D负荷组及内皮损伤组大鼠 胸主动脉内膜厚度均显著增加(P<0.01),中膜厚度减少(P<0.05,P<0.01);3组模型动物胸主动脉组织Ang 水平均显著 高于(以内膜损伤组最高)对照组(P<0.05或P<0.01),且组织Ang 水平与内膜厚度呈显著正相关(r=0.934,P<0.01); 而血浆Ang 水平在各组间无统计学差异。结论:AS的病变程度与大鼠胸主动脉Ang 水平密切相关,而与血浆Ang 水平 无关。提示Ang 水平增高是AS的致病因素之一。

Objective:To investigate the relation between the angiotensinⅡ(AngⅡ)levels in thoracic aorta and plasma and atherosclerosis(AS).Methods:Totally40healthy male Wistar rats were randomly divided into4groups(n=10).Four different feeding methods,including normal diet,high lipid,high lipid+vitamin D overload,and high lipid+vitamin D over-load+endothelium injury,were used for inducing AS in rats.The thickness of intima was taken as the index of AS severity, radio-immunity analysis was used to assay AngⅡin each group in thoracic aorta and plasma.Results:Only rats in high lipid diet group did not develop AS plaque;high lipid+vitamin D only resulted in AS fibrous plaque with VSMC proliferation;high lipid+vitamin D+endothelium injury formed ripe AS plaque.The thickness of intima and AngⅡof thoracic aorta in-creased gradually compared with control group(P<0.01).The AngⅡof plasma was not different among all the groups.Ang Ⅱin thoracic aorta had positive relation with the thickness of intima(r=0.934,P<0.01).Conclusion:The AngⅡlevel in thoracic aorta,but not in plasma,has close relation with AS severity,which indicates that AngⅡis one of etiological factors of AS. [