不同年龄小鼠缺血性心力衰竭后心室重塑程度的比较

摘要

AIM:To observe ventricular remodeling induced by ischemic heart failure in the mice at different ages.METHODS:Three-month-old (young group,n =50) and 18-month-old (old group,n =50) male C57BL./6J mice were selected in the study.Forty mice underwent ligation of left coronary artery with certain infarct size,and 10 were shamoperated for control.Echocardiography was performed after 8 weeks of infarction.All mice were killed and the hearts were collected for examinations.Masson trichrome staining was used to detect myocardial fibrosis.The expression of type Ⅰ and type Ⅲ collagens was measured by the method of immunohistochemistry.RESULTS:The incidences of cardiac rupture (18％ vs 10％,P＜0.05) and heart failure (22％ vs 10％,P＜0.05) were significantly higher in aged mice than those in young mice.The degrees of left ventricular dilation,contractile dysfunction and heart rate were significantly higher in aged mice than those in young mice (P ＜ 0.05).The left ventricular mass index,collagen volume fraction,the expression of type Ⅰ collagen and ratio of type Ⅰ / Ⅲ collagens were significantly increased in aged mice as compared with young mice (P ＜ 0.05).CONCLUSION:After heart failure,aged mice show abnormal collagen distribution,and suffer from worse cardiac functions and more serious ventricular remodeling.%目的:研究不同年龄小鼠缺血性心衰后心室重塑程度的变化.方法:选择3月龄和18月龄的雄性C57BL/6J小鼠共100只,每个月龄组50只,在2组中分别随机选取40只,结扎左冠状动脉定量控制心梗面积,建立稳定缺血性心衰模型,每组其余10只作为假手术组,于术后8周行心脏超声评价各组心功能变化；称量全心脏及左心室重量并计算左心室质量指数(LVMI)；免疫组化检测心肌Ⅰ、Ⅲ型胶原表达,Masson染色检测心肌纤维化的程度并计算心肌间质胶原分数(CVF).结果:与低龄组相比,老龄组心脏破裂率(18％vs10％)和心力衰竭死亡率(22％vs10％)均高于低龄组(P＜0.05)；老龄组心室腔明显增大,心率较快,左室短轴收缩功能障碍更明显(P＜0.05)；老龄组LVMI明显增加(P＜0.05)；老龄组CVF、Ⅰ型胶原的表达以及Ⅰ/Ⅲ型胶原的比值显著高于低龄组(P＜0.05).结论:老龄小鼠缺血性心衰后心肌胶原分布异常,心室重塑程度更重,心功能降低更明显.