【摘要】 目的探讨血管回声跟踪技术评价兔高脂喂养不同阶段腹主动脉结构和弹性变化规律。方法把24只大耳白兔随机平均分成正常对照组(A组),高脂喂养4周组(B组)、8周组(C组)、12周组(D组),分别于高脂喂养4、8、12周末超声检测兔腹主动脉血管结构及弹性,各参数测值与对照组进行比较;超声检测和采静脉血后,将各组兔处死,取兔腹主动脉行病理学分析。结果B、C、D组总胆固醇、低密度胆固醇水平较对照组明显升高,高密度胆固醇较对照组明显降低(P<0.05)。C、D组腹主动脉弹性参数测值与A组比较差异有统计学意义(P<0.05或P<0.01)。常规超声扫查显示,A、B、C组兔腹主动脉内膜光滑,内中膜厚度正常、均匀,未见斑块回声;D组兔腹主动脉内膜不光滑、毛糙、回声增强,内中膜不均匀增厚,局部可见呈偏心状小斑块。光镜下观察:A、B组兔腹主动脉内皮细胞连续完整,内弹力膜连续,无分层,无断裂;C组兔腹主动脉内膜及内皮细胞增生,可见多层泡沫细胞突入管腔,内弹力膜可见部分中断;D组兔腹主动脉内皮细胞不连续性缺失,内弹力膜中断,平滑肌细胞向内膜增生,可见斑块突向管腔。结论兔动脉粥样硬化早期光镜下仅出现泡沫细胞时,血管硬度已出现异常,粥样斑块出现时血管硬度进行性增高,提示诊断早期动脉粥样硬化血管硬度参数比形态学指标更敏感。更多还原

【Abstract】 Objective To study the structures and elasticity in the early stage of atherosclerosis of the abdominal aorta in rabbits.Methods Twenty four Chinese white ear rabbits were randomly divided into four groups(6 rabbits in each):control group,cholesterol diet 4 weeks group,cholesterol diet 8 weeks group and cholesterol diet 12 weeks group.The structures and indices of elasticity were measured with echo-tracking(ET) technique using high resolution Aloka prosound α-10 and the blood lipids and pathology were detected.Results Blood TC、LDL-C were elevated and HDL-C was lowered significantly in the rabbits of the cholesterol diet model groups(P<0.05).The values of β,EP,PWVβ were increased and AC was decreased significantly in both the 8-week and 12-week groups compared with the controls(P<0.05),however,the IMT and atherosclerotic plaques were clearly observed on ultrasound in the 12-week group,but was not detected in the other two groups.Histologically,a thin layer of foamy cells in the intima was only observed in the 8-week group,however,in the 12-week group,the thickened intima was apparently composed of a lot of foamy cells and smooth muscle cells.Conclusions During the early atherosclerotic stage,the arterial stiffness might precede the morphological changes that the foam cells and hyperplastic smooth muscle cells protrude from the intima into the arterial lumen.The vessular stiffness has been already abnormal,when the serum lipid level is high,and the fatty streak appears on the intima.We conclude that the vascular stiffness had been abnormal when fatty streak appears,which is a predictive index of early atherosclerosis.The ET parameters are more sensitive than those of morphology.更多还原