Evaluation of coronary artery hemodynamics and its relationship with atherosclerosis in west diet fed LDL-R knockout mice by ultrasound bio-microscopy

Objective To evaluate the relationship between atherosclerosis and hemodynamic of coronary artery in mice detecting by ultrasound bio-microscopy flow imaging. Methods Double 14 20-week-old LDL-R-/- and C57BL/6 male mice were selected, and randomly divided into two groups in each genotype according to weight. Each two groups were fed to 28 weeks or 36 weeks age respectively with west diet. Coronary artery hemodynamics in these mice were assessed in vivo by Vevo®2100 ultrasound imaging system, then the intima-media thickness(IMT) of aorta in histopathology were analyzed. The differences of coronary artery hemodynamic parameters such as maximum velocity (Vmax), mean velocity (Vmean) and velocity time integral (VTI) were compared between mice of different genotypes of the same week and mice of different weeks of the same genotype. And the relationship between coronary artery hemodynamic in ultrasound and aortic IMT in histopathology were analyzed. Results ①All coronary hemodynamic parameters in LDL-R-/- mice were significantly lower than those of wild-type mice except the Vmax between two 28-week-old genotypes group at the same weeks of age of different genotypes (all P 0.05). ②The histopathological measurements of aortic IMT in LDL-R-/- mice were significantly higher than those of wild type mice(all P<0.05), and those of 36-week-old mice were significantly higher than those of 28-week-old mice(all P<0.05). ③All coronary hemodynamic parameters such as Vmax, Vmean and VTI were negatively correlated with pathological measurements of aortic IMT (r=-0.532, -0.423, -0.524; all P<0.05). Conclusions The parameters of coronary artery hemodynamics obtained by ultrasound bio-microscopy are well correlated with the pathological results of atherosclerosis. Ultrasound bio-microscopic flow imaging can be used as a new method to evaluate the degree of atherosclerosis in mice by detecting the hemodynamic parameters of coronary artery. Key words: Ultrasound bio-microscopy; Mice; Coronary artery; Hemodynamics; Atherosclerosis