摘要
目的研究急性缺血心肌缝隙连接蛋白43(Cx43)、细胞内钙离子浓度([Ca2+]i)及凋亡的变化规律,探讨急性缺血性心律失常的发生机制。方法雄性SD大鼠30只,随机分为假手术组、急性心肌缺血15 min(Is1)及30 min(Is2)组,每组10只。记录各组大鼠室性心律失常的发生情况、心肌Cx43去磷酸化表达、[Ca2+]i及细胞凋亡,建立相关性分析。结果 Is1组室性心律失常较假手术组显著增加;Is2组则更严重。Cx43去磷酸化水平,Is1组较假手术组有所提高,但无统计学差异;Is2组则出现显著增加(P<0.01)。与假手术组比较,[Ca2+]i及凋亡率从缺血15 min开始即显著增加(P<0.01)。Is1组室性心律失常严重程度与Cx43去磷酸化、[Ca2+]i呈显著性正相关;Is2组则与上述两指标及凋亡率均呈显著性正相关。结论心肌[Ca2+]i及凋亡增加可能是急性心肌缺血早期室性心律失常的主要机制;而随后Cx43的变化也参与了其发生。
Objective To investigate the variations of connexin43 （ Cx43）, [Ca^2＋ ]i and apoptosis of ventricular myocardium in acute ischemic condition, and elucidate the underlying mechanisms of acute ischemic arrhythmias. Methods Thirty male SD rats were randomly divided into the sham group, acute myocardial ischemia for 15 min group （ Is1 ） and for 30 min group （Is2） respectively （ all group, n = 10）. The incidences, durations and number of the ventricular arrhythmias, the expressions of Cx43 dephosphorylation, [ Ca^2＋ ]i and apoptosis of myoeardium were all studied. Then, we analyzed the corresponding relations between ventrieular arrhythmias and other values. Results Ventricular arrhythmia significantly of Isl group increased comparing with the sham group; after 30 min of isehemia, the arrhythmias were more serious. Cx43 dephosphorylation of Isl group was higher than the sham group, but without significance. After coronary artery being ligated for 30 rain, this value was significantly raised （ P 〈 0.01 ）. Compared to the sham group, [ Ca^2＋ ]i and apoptotic rate were increased from 15 min of isehemia （P 〈 0.01 for all）. Correlation analysis revealed that severity score of arrhythmias of Isl group was significantly correlated with Cx43 dephosphorylation, [ Ca^2＋ ]i, but not apoptotie rate, while in Is2 group, the severity score of arrhythmias was significantly correlated with all of them. Conclusion Intracellular calcium and apoptosis may be the main mechanism of ventricular arrhythmias in the early phase of myocardial ischemia, and in the later phase Cx43 may also be involved.
出处
《中国心脏起搏与心电生理杂志》
北大核心
2011年第4期349-352,共4页
Chinese Journal of Cardiac Pacing and Electrophysiology
