张文昶,赵长林,郑振达,陈纯波,吴书林
ZHANG Wen-Chang1,ZHAO Chang-Lin1,ZHENG Zhen-Da1,CHEN Chun-Bo2, WU Shu-Lin2 (1.Division of cardiology

• 1:中山大学附属第三医院特诊科
• 2:广东省人民医院心内科

摘要(Abstract)：

目的研究血管紧张素Ⅱ2型受体(AT2)对单个人心房颤动心房肌细胞瞬间外向钾电流(Ito1)的影响。方法选择择期行心脏体外循环手术的持续性心房颤动(>6个月)患者,建立体外循环前取右心耳组织约0.3cm3,放入氧饱和的4℃心脏停搏液中,5min内送回实验室。用胶原酶Ⅱ两步酶解法分离出单个心房肌细胞,用标准的全细胞膜片钳技术记录瞬间外向钾电流,观察0.5mmol/LCGP42112及0.5mmol/LPD123319引起单个人心房颤动心房肌细胞瞬间外向钾电流(Ito1)改变。结果窦律空白对照组Ito1峰值电流密度为(12.73±7.75)pA/pF(n=7),房颤空白对照组Ito1峰值电流密度为(4.42±1.62)pA/pF(n=8),心房颤动空白对照组Ito1峰值电流密度明显降低(P<0.05)。CGP42112灌流前后窦律组及心房颤动组Ito1峰值电流密度无明显变化(P>0.05);PD123319灌流不影响窦律组及心房颤动组Ito1峰值电流密度(P>0.05)。结论心房颤动患者心房肌细胞Ito1电流密度较窦律患者减少,心房颤动致Ito1通道的电生理特性改变。AT2受体激活和失活均不改变窦律患者和心房颤动患者心房肌细胞Ito1通道电流密度,表明Ito1的下调不完全通过AT2介导。
Objective To determine the effect and mechanism of angiotensin Ⅱ receptor type 2 on Transient outward K+ current remodeling in humans atrial myocytes.Methode Whole-cell pacth-clamp recording technique was used to record Ito1 in humans atrial myocytes.Results The Ito1 was recorded in humans atrial myocytes.The effects of CGP 42112 and PD 123319 on current densities of Ito1.The peak current densities of Ito1 in AF group was lower than those in SR group [(4.42±1.62)pA /pF(n=8)vs(12.73±7.75)pA /pF(n=7),P<0.05]. CGP 42112 had no effect on the peak current densities of Ito1 in SR group (12.99±7.75 pA /pF vs 12.73±7.75 pA /pF,n=7,P>0.05) and in AF group(4.14±0.74 pA /pF vs 4.42±1.62 pA /pF,n=8,P>0.05).PD 123319 had no effect on the peak current densities of Ito1 in SR group (11.83±7.90 pA /pF vs 12.99±7.75 pA /pF,n=7,P>0.05) and in AF group (3.68±0.52 pA /pF vs 4.14±0.74 pA /pF,n=8,P>0.05).Conclusion Selective AT2 agonist and antagonist has no effect on the current densities Ito1 in AF and SR groups.

关键词(KeyWords)： 心房颤动;心房肌细胞;血管紧张素Ⅱ2型受体;瞬间外向钾电流;全细胞膜片钳技术
atrial fibrillation;angiotensin II type 2 receptor; transient outward K+ current; humans atrial myocytes; whole-cell patch-clamp.

Abstract:

Keywords:

基金项目(Foundation):

作者(Author): 张文昶,赵长林,郑振达,陈纯波,吴书林
ZHANG Wen-Chang1,ZHAO Chang-Lin1,ZHENG Zhen-Da1,CHEN Chun-Bo2, WU Shu-Lin2 (1.Division of cardiology

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