低密度脂蛋白受体基因敲除小鼠主动脉粥样硬化超声生物显微镜血管成像研究

Ultrasound biomicroscopy imaging of aortic atherosclerotic in the LDL-R gene knock-out mouse

目的利用超声生物显微镜（UBM）动态观察低密度脂蛋白受体（LDL—R）基因敲除小鼠主动脉粥样硬化过程，通过血管成像技术监测主动脉内中膜厚度（IMT）及斑块变化。方法16周及24周雄性LDL—R基因敲除小鼠各10只为实验组，16周及24周雄性C57BL／6小鼠为对照组，用UBM观察小鼠主动脉根部、升主动脉、主动脉弓和颈总动脉形态结构，测量主动脉弓及颈总动脉内径，并于主动脉根部（定位于主动脉瓣上100μm处）及颈动脉分叉部测量内中膜厚度（IMT），与相对应血管节段的病理组织学进行对比分析。结果16周的LDL—R基因敲除小鼠主动脉根部IMT与同龄对照组差异无统计学意义，24周的LDL-R基因敲除小鼠主动脉根部IMT与同龄对照组及16周LDL-R基因敲除小鼠比较差异有统计学意义（P〈0．01）。结论UBM能够动态观察LDL—R基因敲除小鼠主动脉粥样硬化的病理变化。

Objective To detect the atherosclerotic progression in low-density lipoprotein receptor （LDL-R） gene knock-out mouse by ultrasound biomicroscopy（UBM） technique,and to monitor the intima- media thickness （IMT） and changes in plague of aortic wall. Methods 10 male LDL-R gene knock-out mice of 16 weeks age and 10 LDL-R gene knock-out mice of 24 weeks age were in the experimental group,and 10 male C57BL/6 mice of 16 and 24 weeks age were in the control group. The shapes of their aortic roots, ascending aorta,aortic arch and CCA were detected by UBM,and the IMT at aortic root view and carotid artery bifurcation were measured, then the data were compared with histopathology of the corresponding vascular segments. Results The difference between the IMT of aortic root and carotid artery bifurcation of the 16-week-old LDL-R mice and the control group of the same age had no statistical significance. The difference between the IMT of carotid artery bifurcation of the 24-week-old LDL-R mice and the control group of the same age had no statistical significance. The IMT of aortic root thickened compared with control group of the same age （ P〈0.01）. Conclusions The UBM technique can be used to detect the atherosclerotic progression in LDL-R gene knock-out mouse.