心脏骤停复苏猪心肌闰盘超微结构变化的研究  

Change of intercalated disc ultrastructure in porcine myocardium after resuscitation from cardiac arrest

作　　者：刘亚华[1] 王立祥[1] 郭晓东[1] 王运平[1] 周满红[2] 马立芝[1] 沈洪[3] 

机构地区：[1]武警总医院急救医学中心,北京100039 [2]遵义医学院附属医院干部保健病房,贵州遵义563000 [3]解放军总医院急诊科,北京100039

出　　处：《中国急救医学》2014年第2期166-170,I0002,共6页Chinese Journal of Critical Care Medicine

基　　金：卫生行业基金科研专项（201002011）

摘　　要：目的 观察室颤致心脏骤停猪复苏存活24 h后心室心肌细胞肌节排列和细胞间闰盘结构的变化,探讨钙蛋白酶（Calpain）对心肌超微结构的影响及通过调节缝隙连接蛋白43（Cx43）影响心肌信号传导通路的机制.方法 健康家猪14只,随机分为假手术组（n=5）和复苏组（n=9）.复苏组经电刺激建立猪心脏骤停模型,室颤9 min后进行胸外按压CPR,复苏成功5只,存活24 h处死,取心室肌游离壁.透射电镜观察超微结构变化,免疫荧光法观察Cx43表达水平和分布的变化;RT-PCR检测Cx43和Calpain mRNA水平;Western Blot检测p-Cx43、Cx43和Calpain的蛋白表达改变.结果 与假手术组比较,复苏组心肌纤维、肌节排列和闰盘分布较紊乱;心肌细胞间Cx43端-端分布减少、侧-侧分布增多;复苏组Calpain mRNA及蛋白水平均明显增高（P〈0.01）,Cx43 mRNA及蛋白水平均明显降低（P〈0.01）,p-Cx43蛋白水平明显降低（P〈0.01）;p-Cx43/Cx43差异无统计学意义（P〉0.05）.结论 心脏骤停复苏猪心肌Calpain mRNA水平及蛋白表达的增高,促进了对结构蛋白的分解,造成心肌纤维排列异常,同时影响了缝隙连接内Cx43的表达及分布,而通过总Cx43中p-Cx43水平的增加,复苏后心肌细胞间缝隙连接有代偿性的功能恢复.Objective To investigate porcine ventricular changes （sarcomere arrangement and intercalated disc structures） after resuscitation from ventricular fibrillation - induced cardiac arrest, to clarify the effects of calpain in the ultrastructure of cardiac muscles, and the effects of Cx43 changes on signal transmission pathways in cardiac muscles. Methods Five pigs received sham operations to serve as the sham group. In CPR group, nine healthy pigs were treated by electrical shock to induce ventricular fibrillation and cardiac arrest for 9 min, and then underwent cardiopulmonary resuscitation. There were 5 pigs got restoration of spontaneous circulation after resuscitation and survival for 24 h, the animals were killed and their free ventricular walls were retrieved. The retrieved tissues were analyzed by transmission electron microscopy for ultrastructure, by immunofluorescence for Cx43 expression and distribution, by RT - PCR for the mRNA level of Cx43 and calpain, and by western blotting to determine the levels of p - Cx43, Cx43, and calpain. Results Compared with the sham group, the CPR group showed a more irregular arrangement of cardiomyocytes, sarcomeres, and intercalated discs. Moreover, the Cx43 fluorescence distribution in CPR group had fewer end - to - end cardiomyocyte connections but more side - to - side connections. The mRNA level and protein expression of calpain in CPR group were higher than those of sham group （ P 〈 O. O1 ）, and the mRNA level and protein expression of Cx43 in CPR group were also significantly less than those of sham group （P 〈0.01 ）. The CPR group expressed significantly less p - Cx43 （ P 〈 0.01 ） compared with the sham group. However, the two groups had similar p - Cx43/Cx43 ratios. Conclusion After cardiac arrest - resuscitation, the calpain overexpression leads to the degradation of structural proteins and disruption of cardiomyocytes arrangement. The overexpression of calpain also reduces the Cx43 expression and disrupts its distribution. After resuscitati

关 键 词：室颤 心肺复苏 缝隙连接 钙蛋白酶(Calpain) 缝隙连接蛋白43(Cx43) 

分 类 号：R541.7[医药卫生—心血管疾病]