乙酰胆碱激活钾电流对心肌细胞膜电压的影响

Effect of Acetylcholine Activated Potassium Current on Membrane Voltage of Cardiomyocytes

以ZHANG等人构建的完整兔子心脏解剖模型为研究对象,通过五点差分法进行数值积分,采用计算机仿真模拟动态观察心房肌细胞动作电位的变化,揭示乙酰胆碱激活钾电流与心房颤动之间关系。模拟显示,一方面,迷走神经释放的乙酰胆碱浓度过高,可使心房肌细胞的动作电位时程缩短,自律性降低,心律减慢,乙酰胆碱激活的钾电流通道被过度激活;另一方面,乙酰胆碱激活的钾电流上调,动作电位起搏活性降低,传导出现阻滞。上述结果表明,乙酰胆碱激活的钾电流是心房肌细胞重要的离子电流,对心房颤动等心律失常有重要影响。对其功能调节和机制的研究可为了解人类心脏疾病的发生和治疗奠定基础。

In this paper,a complete cardiac anatomical model of rabbit is constructed by Zhang et al.as the research object,the five-point difference method is used for numerical integration,and the changes of action potential of atrial myocytes are dynamically observed by computer simulation,to reveal the relationship between acetylcholine activated potassium current and atrial fibrillation.The results showed that,on the one hand,the high concentration of acetylcholine released by vagus nerve,which can shorten the action potential duration of atrial myocytes,reduce the autonomy,slow down the heart rhythm and over activate the acetylcholine activated potassium current channel.On the other hand,the acetylcholine activated potassium current was up-regulated,action potential pacing activity decreased,and conduction block appeared.The results indicate that the acetylcholine activated potassium current is an important ionic current in atrial myocytes,which have an important impact on arrhythmias such as atrial fibrillation.The study of its functional regulation and mechanism lays a foundation for understanding the occurrence and treatment of human heart diseases.