目的 了解犬急性心肌梗死(AMI)后梗死周边区心肌组织中超极化激活环核苷酸门控阳离子通道亚单位(HCN)2、4 mRNA和蛋白表达的动态变化以及胺碘酮对其表达的影响.方法 通过结扎犬左冠状动脉前降支建立AMI模型,将成功建模的犬随机分为24 h组、1周组、2周组、4周组、胺碘酮组,同时于各时间点均设立假手术组,每组5只.于各时间点末取左心室梗死周边区心肌组织样本(假手术组取左心室相应部位的心肌组织),Real-time PCR检测各组HCN2、HCN4 mRNA的表达, Western-blotting检测HCN2、HCN4蛋白表达.结果 梗死周边区心肌组织中HCN2、HCN4 mRNA和HCN2蛋白的表达在梗死后24 h均呈上升趋势,于梗死后1周达峰值,之后逐渐下降,梗死后4周HCN2、HCN4 mRNA以及HCN2蛋白的表达仍高于假手术组(P＜0.01).胺碘酮组HCN2、HCN4 mRNA和HCN2蛋白的表达显著低于梗死后4周组(P＜0.05).各组均未检测到HCN4蛋白的表达.结论 AMI后左心室梗死周边缺血区心肌组织HCN2、HCN4通道mRNA和HCN2蛋白的表达呈动态变化趋势,在梗死后1周表达达到最高值.胺碘酮可以逆转梗死周围区HCN2、HCN4 mRNA和HCN2蛋白表达,这可能是其抗心律失常的机制之一.%Objective To observe the dynamic changes of hyperpolarization-activated cyclic nucleotidegate channel(HCN) gene and protein expressions in acute myocardial infarction (AMI) canine and the effect of amiodarone on them. Methods The canines were randomly divided into 24-hour group, l-week group, 2-week group ,4-week group after AMI, and amiodarone group. Real-time quantitative polymerase chain reaction (Real-time PCR) and Western Blot were used to measure the mRNA and protein expressions of HCN2 and HCN4 in the heart tissues of the canines in each group. Results The expressions of HCN2, HCN4 mRNA and HCN2 protein were upregulated in 4-week group after AMI ,as compared with those in sham operation group. The expression of HCN2,HCN4 mRNA and HCN2 protein in amiedarone group was significantly decreased,as compared with that in 4-week group after AMI. Conclusion The expression of HCN2 and HCN4 mRNA and protein is increased after acute myocardial infarction. However, the expression of HCN2 and HCN4 is decreased by application of amiedaron, which may be the possible antiarrhythmic action mechanism.
展开▼
