高频超声心动图评价IGFBP-4转基因小鼠心肌梗死后心脏功能的变化

Assessment of cardiac function of IGFBP-4 transgenic mice with myocardial infarction by high-frequency echocardiography

目的探讨高频超声心动图在胰岛素样生长因子结合蛋白-4(insulin-like growth factor binding protein-4,IGFBP-4)转基因小鼠心肌梗死后心脏功能评估中的作用。方法实验分为对照组(n=27)和IGFBP-4转基因组(n=27)。通过结扎冠状动脉左前降支建立心肌梗死模型,于模型建立前,建立后1、2周分别使用高频超声心动图进行心功能评估,比较两组心肌梗死前后心功能变化差异。2周后处死小鼠进行病理学检查,并称取左心室质量,与高频超声左心室质量测量值进行相关性检验。结果结扎术后,超声心动图检查发现两组小鼠心功能较术前明显降低,左心室射血分数(ejection fraction,EF)及左心室短轴缩短率(fractional shortening,FS)较术前降低(均P<0.05),左心室舒张末直径及收缩末直径较术前增大(均P<0.05);术后2周,超声心动图检查发现IGFBP-4转基因组小鼠EF及FS值高于对照组(P<0.05),左心室舒张末直径及收缩末直径大于对照组(P<0.05)。超声心动图测得左心室质量与尸解左心室质量实际值相关性较好,对照组及IGFBP-4转基因组r值别为0.89与0.93。结论高频超声心动图能够用于准确评价IGFBP-4转基因小鼠心肌梗死模型心脏功能的变化。

Objective To assess the cardiac function of insulin-like growth factor binding protein-4（ IGFBP-4） transgenic mice with myocardial infarction by high-frequency echocardiography.Methods The myocardial infarction was induced by ligation of left anterior descending coronary artery in ICR male mice（ control group,n = 30） and IGFBP-4 transgenic mice（ n = 30）. The cardiac function was assessed by high-frequency echocardiography before and 1,2 weeks after modeling. The mice were sacrificed for pathological examination and left ventricular mass（ LVM） weighing. The relevance of LVM value measured by high-frequency echocardiography and that of postmortem examination was analyzed. Results Echocardiography showed that（ ejection fraction） EF and（ fractional shortening） FS value decreased（ P〈0.05） while（ left ventricular internal diameter at end diastolic） LVIDd and（ left ventricular internal diameter at end systolic） LVIDs increased markedly（ P〈0.05） after modeling. And the reduction of EF and FS value in IGFBP-4 transgenic mice was significantly lower than that in the control group（ P〈0.05）; the enlargement of LVIDd and LVIDs was also lower than that of control group（ P〈0. 05）. The LVM value measured by high-frequency echocardiography was closely correlated with that examined by postmortem both in control group（ r = 0.89,P〈0.01） and in IGFBP4 group（ r = 0.93,P〈0. 01）. Conclusion The cardiac function change of IGFBP-4 transgenic mice group can be accurately assessed by high-frequency echocardiography.