应用单相动作电位研究房颤模型心房电重构的发生机制  

Mechanism of atrial electrical remodeling in atrial fibrillation model investigated by monophasic action potential

作　　者：杨贵荣[1] 张薇[2] 黎莉[2] 钟明[2] 朱慧[2] 张运[2] 

机构地区：[1]武警总医院重症监护科,北京市100039 [2]山东大学齐鲁医院心内科,济南市250012

出　　处：《中华老年多器官疾病杂志》2010年第5期445-448,共4页Chinese Journal of Multiple Organ Diseases in the Elderly

基　　金：国家自然科学基金资助项目(No.30370564);山东省科技攻关资助项目(2005GG3202162)

摘　　要：目的应用单相动作电位（MAP）技术检测心房颤动模型电生理参数改变的特点,探讨房颤电重构发生的分子机制。方法健康杂种犬17只,随机分为房颤组（n=11）和对照组（n=6）。房颤组安装固定频率起搏器,以350~430次/min的频率快速心房起搏,对照组行假手术。于起搏前和8周后测量右房有效不应期（AERP）和单相动作电位,测量单相动作电位振幅（MAPA）、单相动作电位时限（MAPD）、复极90%时动作电位时限（MAPD90）、复极50%时动作电位时限（MAPD50）、复极90%动作电位时限与复极50%动作电位时限之差（MAPD90-50）。原子发射光电直读光谱法测定心房肌组织Ca2＋含量。RT-PCR法检测心房肌浆网Ca2＋-ATP酶和L型钙通道mRNA转录水平。结果对照组MAP时相明显。房颤组MAP形态发生改变。与对照组相比,房颤组MAPA有下降趋势;MAPD,MAPD90,MAPD50,MAPD90-50分别缩短13.79%,19.65%,13.59%和31.25%。MAPD,MAPD90,MAPD90-50与右房心肌Ca2＋呈显著负相关;MAPD90-50与L型钙通道显著正相关。上述指标与肌浆网钙ATP酶均无相关性。结论 MAP是研究房颤电重构的可靠手段。Objective To investigate the molecular mechanism and characteristics of atrial electrical remodeling parameters in atrial fibrillation（AF） model using monophasic action potential（MAP）.Methods Seventeen mongrel dogs were randomly divided into two groups.Eleven dogs were subjected to rapid right atrial pacing（350-430 beats/min） for 8 weeks（AF group）,and another 6 sham-operated dogs served as controls.Before and after 8 weeks pacing,electrophysiological examinations were performed to calculate atrial effective refractory period（AERP）.The MAP amplitude（MAPA）,duration（MAPD）,90% repolarization duration（MAPD90）,50% repolarization（MAPD50） and MAPD90-50 were measured according to MAP recordings.The content of myocardial calcium was assayed by spectrocomparator in atrial myocardium from all dogs.The messenger ribonucleic acid（mRNA） level of sarcoplasmic reticular（SR） Ca2＋-ATPase and L-type calcium channel were measured by reverse transcription-polymerase chain reaction（RT-PCR） and normalized to the mRNA level of β-actin.Results Each phase of MAP was easily discerned in control dogs.Morphology of MAP was significantly changed in AF group.Compared with control group,MAPA of AF group had a tendency to decrease.MAPD,MAPD90,MAPD50 and MAPD90-50 were shortened by 16.20%,19.65%,13.59% and 31.25%,respectively.MAPD,MAPD90 and MAPD90-50 were negatively correlated to the content of calcium in right atrial myocardium.MAPD90-50 was positively correlated to the mRNA level of L-type calcium channel.All parameters had no relation to mRNA level of SR Ca2＋-ATPase.Conclusion MAP provides a reliable method to investigate atrial fibrillation electrical remodeling.Changes in L-type calcium channel and SR Ca2＋-ATPase may be one of the mechanism of atrial electrical remodeling.

关 键 词：心房颤动 电重构 单相动作电位 L型钙通道 CA2+-ATP酶 

分 类 号：R331.38[医药卫生—人体生理学]