【摘要】 目的利用超声彩色多普勒技术对构建的大鼠腹主动脉缩窄(abdominal aortic constriction,AAC)模型进行检测,评价动物模型的心脏结构、功能变化。方法以0.3 mm银夹缩窄双侧肾动脉上段(约0.5 cm处)的腹主动脉制备压力超负荷大鼠模型36只,按时间分为AAC-2周组、AAC-4周组和AAC-8周组及假手术(Sham)组(每组12只)。建模后2周、4周和8周时,用Vevo 2100型动物微小超声心动图仪进行M-mode超声检测心功能指标,如射血分数(ejection fraction,EF)、左心室短轴缩短率(fractional shortening,FS)、左心室舒张期前壁厚度(left ventricular end-diastolic anterior wall thickness,LVAWd)、左心室收缩期前壁厚度(left ventricular endsystolic anterior wall thickness,LVAWs)、左心室舒张期后壁厚度(left ventricular end-diastolic posterior wall thickness,LVPWd)、左心室收缩期后壁厚度(left ventricular end-systolic posterior wall thickness,LVPWs)、左心室舒张末期内径(left ventricular end-diastolic internal dimension,LVEDd)、左心室收缩末期内径(left ventricular endsystolic internal dimension,LVEDs);和超声彩色多普勒测量腹主动脉缩窄前、后的血流量,二尖瓣E/A值;测量左心室质量指数(left ventricular mass index,LVMI)等。结果(1)同Sbam组比较,AAC-2周组的EF、FS、LVEDd、LVEDs明显降低(P<0.01),而LVAWd、LVAWs、LVPWd、LVPWs均明显增加(P<0.05);腹主动脉缩窄前段血流量与管腔增大,缩窄后段血流量和管腔显著变小;且出现E/A值和LV MI改变明显(P<0.01),AAC-2周组左心室肥厚明显。(2)同AAC-2周组比较,AAC-4周和AAC-8周组EF、FS、LVAWd、LVAWs、LVPWd、LVPWs明显降低,而LVEDd、LVEDs明显增加,且缩窄后段血流速度、血流量明显变小,而E/A值及LVMI增加明显(P<0.05)。AAC-4周组与AAC-8周组心脏体积、左心室腔明显增大呈心力衰竭病变。结论利用动物微小彩色多普勒技术能直观、准确地检测和评价以银夹缩窄腹主动脉的大鼠模型;AAC模型2周时心肌肥厚明显、4周时出现心力衰竭,8周时心力衰竭严重。更多还原

【Abstract】 Objectives To determine the changes of cardiac structure and function in a rat model of abdominal aortic constriction(AAC) by color Doppler echocardiography assay.Methods A rat model of AAC was established by fixing a 0.3 mm silver clip at the bilateral renal artery(located at about 0.5 cm from the top).Thirty-six survived rats were randomized into 2-week AAC(AAC-2W) group,AAC-4W group,AAC-8W group and sham operation(Sham) group(12 in each group).At 2 weeks,4 weeks and 8 weeks after AAC surgery,the rats underwent two-dimensional(2D)-guided M-mode transthoracic echocardiography by tiny echocardiography instrument Vevo 2100.The cardiac function variables,including ejection fraction(EF),fractional shortening(FS).left ventricular end-diastolic anterior wall thickness(LVAWd),left ventricular end-systolic anterior wall thickness(LVAWs),left ventricular end-diastolic posterior wall thickness(LVPWd),left ventricular end-systolic posterior wall thickness(LVPWs),left ventricular enddiastolic internal dimension(LVEDd) and left ventricular end-systolic internal dimension(LVEDs) were determined.Blood flows before and after AAC surgery and mitral E/A ratios were measured by color Doppler assay.Left ventricular mass index(LVMI) was also measured.Results(1) Compared with sham group,variables of EF,FS,LVEDd and LVEDs were significantly lower(P<0.01),while LVAWd,LVAWs,LVPWd and LVPWs significantly increased(P<0.05) in AA.C-2W group.Anterior blood flow before AAC surgery and vascular lumen increased,while posterior blood flow after AAC and vascular lumen significantly decreased,with significant changes of E/A ratios and LVMI(P<0.01).Left ventricular hypertrophy appeared in 2 weeks after AAC surgery.(2) Compared with AAC-2W group,EF,FS,LVAWd,LVAWs,LVPWd and LVPWs significantly reduced,while LVEDd and LVEDs significantly increased in AAC-4W group and AAC-8W group.Posterior blood flow velocity after AAC and blood flow volume significantly decreased after AAC surgery,with significant increases of E/A ratios and LVMI(P<0.05).Heart volume and left ventricular cavity were significantly expanded in AAC-4w group and AAC-8w group.Conclusions The rat AAC model can be intuitively and accurately detected by the technology of color Doppler echocardiography.Cardiac hypertrophy occurrs at2 weeks after AAC surgery,heart failure occurrs at 4 weeks,and severe heart failure occurrs at 8 weeks.更多还原