犬快速肺静脉起搏心房颤动模型中CalpainⅠ在肺静脉肌袖及左心房的表达及意义

Expression of CalpainⅠ in pulmonary vein myocardial sleeves and left atrium in a canine model of persistent atrial fibrillation by rapid pulmonary vein pacing

目的模拟肺静脉自行发放高频脉冲建立心房颤动的动物模型,研究肺静脉及左心房的CalpainⅠ重构情况,以期阐明CalpainⅠ的变化在持续性房颤的发生和维持中的重要作用。方法30只犬随机分为实验组和对照组,建立犬快速肺静脉起搏持续性心房颤动模型,取组织标本,标本共分4组:①正常犬左心房后壁组;②正常犬左上肺静脉肌袖组;③房颤犬左心房后壁组;④房颤犬左上肺静脉肌袖组。用RT-PCR和W estern印记法分别检测各组的CalpainⅠmRNA和蛋白的表达情况。结果正常犬左心房和肺静脉肌袖的CalpainⅠ的mRNA和蛋白表达水平无明显差异;房颤犬肺静脉和左心房的CalpainⅠ的mRNA和蛋白表达均高于对照组(均P<0.05),房颤犬肺静脉肌袖CalpainⅠ的mRNA和蛋白表达高于左心房后壁部(均P<0.05)。结论在犬快速肺静脉起博心房颤动模型中,CalpainⅠ肺静脉肌袖和左心房中出现重构,参与了房颤的发生和维持。

AIM To investigate the role of Calpain Ⅰ in persistent atrial fibrillation （AF） by establishing a persistent atrial fibrillation （AF） model of canine with rapid pulmonary vein pacing and identifying the changes of CalpainI mRNA and protein level in pulmonary veins and left atrium. METHODS Thirty dogs were randomly divided into 2 groups： normal control group （SR, n = 15 ） and atrail fibrillation group （AF, n = 15）. A persistent atrial fibrillation （AF） model of canine with rapid pulmonary vein pacing was established. Samples were collected from left upper pulmonary veins and left atrium. Samples were divided into four groups ： left atrium of normal control group, left upper pulmonary of normal control group, left atrium of atrial fibrillation group and left upper pulmonary of atrial fibrillation group. The mRNA and protein expression of Calpain Ⅰ were assessed respectively by reverse-transcription quantitative PCR and Western blot. RESULTS No significant differences were found in the expression of Calpain Ⅰ between the normal left upper pulmonary and left atrium. The mRNA and protein expressions of Calpain Ⅰ increased dramatically （P 〈0. 05） in the AF group than that in the SR group, either in pulmonary veins or left atrium. In the AF group, the mRNA and protein expressions of Calpain Ⅰ increased dramatically （P 〈0. 05） in pulmonary veins than that in left atrium. CONCLUSION There is remodeling of Calpain Ⅰ in pulmonary veins and left atrium during AF and the remodeling is involved in the maintenance and stabilization of AF.