几种钾通道阻滞剂的心脏效应  

Cardiac effects of several potassium channels blockers

作　　者：赵丁[1] 任雷鸣[1] 

机构地区：[1]河北医科大学药学院,石家庄050017

出　　处：《中国药理学通报》2000年第3期258-261,共4页Chinese Pharmacological Bulletin

摘　　要：心脏Ito、IK1和IK 通道的分布具有明显的种属差异和组织差异 ,IK 通道至少存在有 3种亚型 ,即IKur、IKr和IKs。Ito、IK1和IK 通道阻滞剂多具有正性肌力作用和负性频率作用。与Ⅰ类抗心律失常药不同 ,IKr通道阻滞剂对迷走神经兴奋所致的心脏电生理效应具有显著的选择性抑制或增强作用。Ito抑制剂选择性地延长心房肌动作电位时程 ;IK 抑制剂延长哺乳动物心房和心室肌有效不应期的作用不同。逆向使用依赖性是目前临床应用的Ⅲ类抗心律失常药物 (主要作用于IKr)主要缺点 ,它可能与心率加快时IKs的累积有关。并用IKs阻滞剂或并用 β受体拮抗剂可能提高Ⅲ类抗心律失常药的疗效 ,避免尖端扭转型室性心动过速的发生。Distribution of I to or I K1 or I K channels in heart is significantly different in species and tissues. Three subtypes of I K channels, I Kur , I Kr and I Ks have been identified at least. Most blockers of I to , I K1 and I K produce positive inotropic and negative chronotropic effects in the heart. In contrast to class Ⅰantiarrhythmic agents, I Kr blockers selectively modulate electrophysiological responses to parasympathetic nerve stimulation. I to blockers increase atrial action potential duration selectively, the prolongation by I K blockers of atrial and ventricular effective refractory period in mammalian is different. Reverse use dependence is the main shortage of class Ⅲ antiarrhythmic agents (blockade of I Kr ) used clinically, which may be related to an accumulation of I Ks current at high heart rate. Application of class Ⅲ antiarrhythmic agents together with I Ks blockers or β adrenergic antagonists may increase their therapeutic effects, and decrease the occurrence of TdP.

关 键 词：钾通道阻滞剂 心脏电生理 心率 心肌收缩力 

分 类 号：R972[医药卫生—药品]