超声评价动脉硬化兔血管内皮舒张功能的实验研究

目的应用高分辨力超声检测动脉硬化兔模型髂外动脉内皮舒张功能,探讨血管内皮功能与高脂血症、血浆同型半胱氨酸(Hcy)的关系。方法雄性新西兰大白兔22只,其中正常对照组6只、高胆固醇组8只、高蛋氨酸组8只,高胆固醇组作为阳性对照组。应用ATL5000彩色多普勒超声检测仪检测以上各组兔髂外动脉血管内皮依赖性舒张功能和血管内皮非依赖性舒张功能,并进行病理学检查(光镜和电镜)及血脂(胆固醇、甘油三酯、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇)测定。结果①8周时高胆固醇组血脂水平较其他两组均明显升高(P<0.05),高蛋氨酸组血浆Hcy水平较其他两组明显升高(P<0.05)。②高胆固醇组和高蛋氨酸组髂外动脉内皮依赖性舒张功能和内皮非依赖性舒张功能均较对照组减低(P<0.05)。③各组之间均有相应的病理改变。结论高血脂、Hcy均与血管内皮舒张功能密切相关,Hcy是引起内皮舒张功能障碍的重要独立危险因素,且应用高分辨力彩超评价血管内皮功能的方法简便、准确、无创,易于推广。

Experimental evaluation of endothelium vascular relaxation by ultrasonography in atherosclerotic rabbits

Objective To evaluate the endothelial dependent vascular relaxation in external iliac artery of artherosclerotic (AS) rabbits using ultrasonography, and to investigate the relation between endothelial function and hypercholesterolemia or hyperhomocysteinemia (Hcy). Methods Twenty-two male New Zealand rabbits were randomized into the normal control group (n=6), hypercholesterolemia group (Hcs group, n=8) and hypermethioninemia group (Hmn group, n=8). The Hmn group was set as a positive control. All groups were evaluated for endothelium dependent and independent relaxation of the interested artery with ATL5000 color Doppler ultrasonoscopy, microscopic pathology (EM/LM) and blood lipids (cholesterol, high density lipoprotein cholesterol and low density lipoprotein cholesterol). Results Statistically, ①The level of blood lipid in the Hcs group was higher than that in the others (P<0.05). Level of homocysteinemia in the Hmn group was higher than that in the others (P<0.05). ② Compared with the normal control group, endothelium dependent and independent vascular relaxation in rabbit external iliac artery was lowered in the Hcs and Hmn groups (P<0.05). ③ There were relevant pathological changes in different groups. Conclusion Both hypercholesterolemia and Hcy appeared to correlate with endothelium vascular relaxation. Hyperhomocysteinemia may be an independent important risk factor of AS. Ultrasonography provided an easy, accurate and non-invasive tool for this evaluation.