应用高频超声研究血流剪切力对兔早期动脉粥样硬化的影响

目的探讨血流剪切力对兔早期动脉粥样硬化的影响及其变化规律。方法将60只新西兰大白兔随机分为2组,对照组15只,正常饮食;实验组45只,高脂饮食。各分为3个亚组分别喂养至4、8、12周测量血流剪切力等参数,同期行血脂、血黏度及病理检查。结果实验组兔血脂各项指标显著升高;血液黏稠度随造模时间延长明显升高。同一时间点,与对照组比较,实验组血管内径均有统计学意义(P0.01),收缩期峰值流速及剪切力在12周,舒张期峰值流速及剪切力在4周、8周有统计学意义(P0.01)。结论血流剪切力在早期动脉粥样硬化形成中具有重要作用,舒张期血流力学的改变是动脉粥样硬化形成的重要环节。

Effect of Blood Shearing Stress on the Early Stage of Rabbit Atherosclerosis by High-frequency Ultrasound

Objective To observe the effect of blood shearing stress on the early stage of atherosclerosis and its changing regularity.Methods 60 white New Zealand rabbits were divided into two groups randomly:15 rabbits(control group)were normal fed,while 45 rabbits(experiment group)were fed with high cholesterol diet.Each group was divided into three subgroups that were fed for 4 weeks,8 weeks and 12 weeks respectively.Blood shearing and viscosity parameters,blood lipid levels and pathological examination were proceeded at each time-point.Results The blood lipid levels of the experiment group all increased significantly and the blood viscosity increased along with the time.Compare with the control group at the same time-poind,the vessle diameter increased and the changes were significant in statistics(P<0.01).The systolic peak velocity and shearing stress were statistically different at the 12~th week,while the diastolic peak velocity and shearing stress were stastistic different at the 4~(th) and 8~(th) week.Conclusions The blood shearing stress shows important effect on the early stage of arterosclerosis,and the changes of diastolic hemodynamic changes are important.