摘要目的 应用高频超声测定Wistar大鼠心脏结构和功能,探讨其增龄性改变的规律.方法 选用1、2、5、12、20月龄的雄性健康Wistar大鼠60只(每组12只),各组大鼠分别行经胸超声心动图检查,测定心脏结构与功能参数,最后处死大鼠取左心室称质量.结果 随增龄左心房内径、舒张末期左心室内径、室间隔及左心室后壁厚度、左心室心肌质量均增加(P<0.05),超声评估左心室质量与解剖称左心室质量结果呈正相关(r=0.78,P<0.01),各组左心室射血分数、短轴缩短率差异无统计学意义(均P>0.05);等容舒张时间随增龄延长(P<0.01);组织多普勒二尖瓣环舒张早期峰值(Ea)自2月龄后开始随增龄逐渐下降,舒张晚期峰值(Aa)呈上升趋势,Ea/Aa在1、2、5月龄组>1,12、20月龄组<1.多因素分析结果显示,月龄是左心房内径、舒张末期左心室内径、二尖瓣环舒张早期峰值的影响因素.结论 高频超声能够评价大鼠的心脏结构与功能的改变;老龄大鼠心房、心室内径均增加,左心室壁增厚,收缩功能无明显改变,而舒张功能已减低.

abstractsObjective To determine the cardiac structure and function by transthoracic highfrequency ultrasonography in Wistar rats, and to explore the patterns of age-related changes.Methods Male Wistar rats aged 1, 2, 5, 12, and 20 months (n= 12 each group) underwent transthoracic echocardiographic analysis to examine the parameters of cardiac structure and function.Finally, the rats were sacrificed and the left ventricles were weighed. Results The left atrial dimension (LAD), left ventricular end-diastolic diameter (LVEDD), interventricular septum thickness at diastole (IVSD), left ventricular posterior wall thickness (LVPWd) and left ventricular mass (LVM) increased with age (all P ＜ 0.05 ) . There was a positive relationship between echocardiographic value and the autopsy weight LVM (r=0. 78, P＜0.01). There were no statistical significances in ejection fraction and fractional shortening among groups (all P＞0.05). Isovolumic relaxation time (IVRT) prolonged with age (P＜0. 01). After 2 month-old, tissue Doppler imaging Ea gradually decreased with age, Aa tended to increase with age. Ea/Aa ratio was more than 1 value in 1-, 2- and 5-months-old group, and it was less than 1 value in 12-, and 20-month-old group.Multivariate analysis showed that age was the influence factor of LAD, LVEDd and Ea. Conclusions Transthoracic high-frequency ultrasonography can be used to evaluate cardiac structure and function in rats; In aged rats, the wall-thickness, LAD and LVEDd are significantly increased. There is no significant change in systolic function, but diastolic function is decreased.