多普勒超声评价血流剪切力对血管重构的影响

Evaluation of the Effect of Shear Stress on Vascular Remodeling with Ultrasound Doppler in the Model of Atherosclerotic Rabbits

目的 探讨血流剪切力对动脉粥样硬化血管重构的影响。方法 大耳白兔 2 0只 ,体重 2 .0～ 2 .4kg ,兔龄 5～ 6个月 ,以高脂饮食连续喂养 12周。生化测定Tch、TG、LDL、HDL水平 ,采用多普勒超声测定髂外动脉血流剪切力、内皮依赖性舒张功能 (EDD)、动脉内中膜厚度。结果 与基态相比 ,EDD明显受损 (P <0 .0 1) ;下降的血流剪切力与EDD明显正相关 (r =0 .68) ,与内中膜厚度明显负相关 (r =-0 .75 )。结论 本研究显示长期高脂饮食可导致动脉血流剪切力明显下降 ,低幅血流剪切力与EDD呈正相关 ,与内中膜厚度呈负相关 。

Purpose To determine the effect of shear stress on vascular remodeling in rabbits fed with high cholesterol diet. Methods Twenty big ear white rabbits, weight 2.0-2.4kg, age 5-6 months, were fed with high cholesterol diet for 12 weeks. Biochemical parameters such as Tch?TG?HDL, LDL were measured. Shear stress, endothelium dependent dilation(EDD) and intima media thickness were measured with Doppler ultrasound in iliac arteries. Results In rabbits fed with high cholesterol diet for 12 weeks, EDD(%) of external iliac arteries was injured to a great degree, and intima media thickness increased markedly. Compared with baseline group, shear stress decreased from (15.50±5.68)dynes/cm 2 to (9.76±2.81)dynes/cm 2 and there was a significant correlation between shear stress and EDD, IMT ( r =0.68, r =-0.75 respectively). Conclusion Our study showed that a long term high cholesterol diet would lead to a significant decrease of shear stress, and that low shear stress was positively correlated to injured EDD and negatively correlated to IMT respectively. Low shear stress can affect vascular remodeling in the procession of arterioclerosis.