小鼠急性心肌梗死后心脏破裂的性别差异研究

Gender differences in cardiac rupture after acute myocardial infarction in mice

目的:探讨小鼠急性心肌梗死(AMI)后心脏破裂的性别差异。方法:选择雄性、雌性C57BL小鼠各70只,各自随机分为假手术组和心肌梗死(MI)组。建立AMI模型后,观察不同性别组小鼠心脏破裂发生率;应用病理染色方法,分别于AMI后第3、7天检测炎性细胞浸润程度、心肌间质胶原含量(CVF),并于AMI后第7天行超声和血流动力学检查。结果:(1)AMI后雄性组心脏破裂发生率(34.3%)显著高于雌性组(11.8%)(P<0.05)。(2)与雌性组比较,雄性组AMI后第3天炎性细胞浸润程度明显增加(P<0.05),心肌间质胶原含量较低。(3)AMI后第7天时,雄性假手术组平均动脉压(MAP)、左室收缩压(LVSP)均高于雌性假手术组(P均<0.05),雄性MI组较雌性MI组表现出显著的左室扩张、梗死区变薄、心功能障碍以及血流动力学恶化。结论:小鼠AMI后心脏破裂发生率存在性别差异,雄性明显高于雌性。炎性细胞浸润程度增加、间质胶原含量较低和左室早期重塑恶化可能是雄性小鼠心脏破裂发生率增加的重要原因。

Objective： To investigate gender differences in cardiac rupture after acute myocardial infarction in mice. Methods： C57BL mice in two group： males and females were divided into sham operation group and myocardial infarction（MI） group randomly. Following acute myocardial infarction（AMI） induced by openchest surgery, the cardiac rupture events were monitored. Pathological staining were used to measure the content of collagen and quantitate the inflammatory cells at 3 and 7 days after surgery. The echocardiography and hemodynamics were performed at 7 days after surgery. Results： （1） A significantly higher incidence of cardiac rupture was observed in males than in females （34. 3% versus 11.8%, P〈0.05）. （2） Males had a significantly higher number of inflammatory cells infiltrating at the infarct border at 3 days after surgery （P 〈0.05）. The collagen content were less in males than in females at 3 and 7 days after AMI. （3） The MAP and LVSP in sham operation group were higher in male mice compare to female mice （both P 〈0.05）. And the severe infarct expansion, worse left ventricular （LV） remodeling and hemodynamics were showed in males compared to females at 7 days after surgery. Conclusion： The cardiac rupture rate during the first week after MI was significantly higher in male mice than in female mice. The mechanisms responsible for this gender-related difference in cardiac rupture were related to more infiltrating inflammatory cells, less collagen content, and aggravated early LV remodeling.