GW24-e2260 Ultrasound Biomicroscopy Application in Detecting Coronary Artery Flow in LDL-R-/- Mouse Model of Atherosclerosis

Objectives Hemodynamics parameter of left main coronary artery (LMCA) were studied in LDL-R-/- mice by using Ultrasound biomicroscopy (UBM), and to evaluate the influence of atherosclerosis to the hemodynamics of coronary artery, and the value of UBM in the application. By measuring maximum IMT in the ascending aorta, UBM was capable of following progression of atherosclerosis in AS models mice. Methods Mice that low density lipoprotein receptor gene was knocked out were used, and the wild type mice were used as control animals. Part 1. Normal chow diet: Two different age groups were 28 weeks and 36 weeks (all n = 7). Wild type mice were in the same grouping. All mice had normal chow diet. Part 2. High fat diet: Two groups of LDL-R-/- mice were 28 weeks and 36 weeks (n = 7), with high fat diet 8 and 16 weeks respectively. Wild type mice in the same age were used as normal control groups, and had high fat diet for 8 and 16 weeks, too Diastolic peak velocity(Vmax),mean flow velocity (Vmean) and velocity-time integral (VTI) of LMCA were measured by UBM. The intima-media thickness (IMT) or plaque thickness was measured in the ascending aorta (AAO) short-axis views, and detected corresponding histological thickness in the same vascular section. Results Normal chow diet: Vmax, Vmean and VTI of LDL-R-/- had no difference with the control mice. High fat diet: Vmean and VTI of LDL-R-/- were induced of 28 weeks LDL-R-/- mice than the control group, and Vmax were without difference between LDL-R-/- mice than the control mice. High fat diet: Vmax, Vmean and VTI of LMCA had significant difference between LDL-R-/- and control groups, and all of these flow parameters induced in LDL-R-/- mice. Vmax, Vmean and VTI of LMCA were correlated with the plaque thickness of ascending aorta (r = -0.532, -0.423, -0.524; respectively P <0.01) Conclusions UBM is an efficient noninvasive method for detecting the hemodynamic changes of coronary artery flow in mice. The hemodynamic changes of coronary artery flow are in correlation with atherosclerosis of ascending aorta.