摘要:
Objective: To investigate the wild type(WT) knockout EP3(EP3-/-) mouse cardiac structure and function, ultrasound biomicroscopy(UBM) and speckle tracking echocardiography(STE) were applied, and to understand the important role of EP3 receptor in the changes of dilated cardiomyopathy disease course. Methods: Take conventional ultrasound echocardiography inspection of twenty mice of two groups using the VisualSonics Vevo 2100 Imaging System, collecting two-dimensional(2D) images such as long axis of parasternal left ventricular,short axis of left ventricular papillary muscle level, short axis of aorta and the M mode ultrasound of above 2D images. Conventional ultrasound echocardiography included heart rate(HR), left ventricular end systolic diameter(LVIDs), left ventricular diastolic diameter(LVIDd), left ventricular end systolic anterior wall thickness(LVAWs), left ventricular end diastolic anterior wall thickness(LVAWd), left ventricular posterior wall thickness(LVPWs), left ventricular diastolic posterior wall thickness(LVPWd), left ventricular volume(LV Vols), left ventricular ejection fraction(LVEF), fractional shortening(FS), left ventricular mass(LV mass), mitral E/A(MV E/A), isovolumic relaxation time(IVRT). To evaluate the endocardial and epicardial left ventricular strain by using ultrasound biomicroscopy speckle tracking imaging system and analysis the peak strain of two different sections of left ventricular, epicardial longitudinal strain, circumferential strain and radial strain time to peak(TPK), maximum peak delay time of ventricular wall(MOWD). Results: After examination of 2D and M mode ultrasound, heart function of EP3-/- mice was significantly lower than that of WT mice. Analysis of endocardial and epicardial of left ventricular myocardial strain showed the decreasing trend of the longitudinal, circumferential and radial strain in EP3-/- mice than WT mice. Conclusions: UBM can detect the mouse dilated cardiomyopathy and the structure change of myocardial. And the EP3 receptor plays an important role in the maintenance of cardiac function.%目的:应用超声生物显微镜(ultrasound biomicroscopy, UBM)及斑点追踪(speckle tracking echocardiography, STE)技术探讨野生型(wild type, WT)、EP3基因敲除(EP3-/-)小鼠心肌结构功能的改变,了解EP3受体在扩张性心肌病发病病程以及心肌结构功能改变中的重要作用。方法:用VisualSonics Vevo 2100 Imaging System对两组雄性的C57BL/6小鼠进行检测,获得了清晰的二维(two-dimensional,2D)图像,如胸骨旁左室长轴、左室短轴、主动脉短轴以及2D图像引导的M型超声。彩色多普勒图像常规超声心动图测量包括:心率(heart rate, HR)、左心室收缩末内径(left ventricular end systolic diameter, LVIDs)、左心室舒张末内径(left ventricular diastolic diameter, LVIDd)、左心室收缩末前壁厚度(left ventricular end systolic anterior wall thickness, LVAWs)、左心室舒张末前壁厚度(left ventricular end diastolic anterior wall thickness, LVAWd)、左心室收缩末后壁厚度(left ventricular posterior wall thickness, LVPWs)、左心室舒张末后壁厚度(left ventricular diastolic posterior wall thickness, LVPWd)、左心室容积(left ventricular volume, LV Vols)、左室射血分数(left ventricular ejection fraction, LVEF)、短轴缩短率(fractional shortening, FS)、左心室质量(left ventricular mass, LV mass)、二尖瓣E/A(mitral E/A, MV E/A)、左室等容舒张期时间(isovolumic relaxation time, IVRT)。并用UBM STE成像评价小鼠左心室内外膜心肌应变,脱机分析两个不同切面左心室内、外膜的纵向应变、圆周应变及径向应变的峰值应变(peak systolic strain, PK)、达峰时间(time to peak, TPK)、室壁最大达峰延迟时间(maximum peak delay time of ventricular wall, MOWD)等指标。对各组超声结果进行统计分析,研究EP3受体与小鼠心脏形态及功能之间的关系。结果:2D和M型超声检查小鼠心功能EP3-/-小鼠明显差于WT小鼠。UBM STE成像分析小鼠左心室内外膜心肌应变结果显示EP3-/-小鼠左心室内膜下和外膜下心肌纵向、圆周及径向PK均呈逐渐减小的趋势。结论:UBM可以检测小鼠发生扩张型心肌病病程以及心肌结构的改变,EP3受体亚型在维持心脏功能中具有重要的作用。