三种氨基苷类药物抗牵张性心律失常作用的比较

Comparative Studies on the Antagonistic Effects of Aminoglycosides on Stretch-Induced Arrhythmias

目的 研究3种氨基苷类抗生素链霉素（SM）、庆大霉素（Gen）、丁胺卡那霉素（Ami）抗牵张性心律失常的作用。方法采用膨胀体外灌流大鼠左心室，夹闭体内豚鼠升主动脉，利用标准微电极技术观察药物抗牵张性心律失常的作用和对动作电位的影响。结果SM、Gen、Ami（100-200μmol／L）能缩短心律失常的持续时间；抑制单相动作电位时程（MAPD）的缩短、后除极的产生和触发活动；抑制动作电位（AP）50％和90％复极时程的缩短，且3种药物抗牵张性心律失常作用的差异无显著性意义（P〉0．05）。结论氨基苷类抗生素能抑制牵张诱发的心律失常，主要可能的作用机制为通过阻滞牵张敏感性离子通道（SACs），抑制动作电位时程的缩短和后除极的产生。

Objective To study the antagonistic effects of the streptomycin （SM）, gentamycin （Gen） and amikacin （Ami） on the arrhythmias induced by an transient increase of ventricular wall stress in the heart and compare their potencies. Methyls Inflating the intracavitary balloon, clamping the ascending aorta and standard microelectrode intracellular recording technique were used to observe the effects of aminoglycosides on the arrhythmias and action potential duration （APD）. Results SM, Gen and Aml （100-200μmol/L） could concentra＇tion-dependently reduce the persistent duration of stretch-induced arrhythmias in vivo and in vitro. They also could significantly inhibit the shortening of monophasic APD, APD at 50 % and 90% （APD50 and APD90 ） and trigger activity related to stretch. At the same molar concentration, the differences of their potencies among groups were not significant （P〉0.05）. Conclusion Aminoglycosides can suppress the stretch-induced arrhythmias and antagonize the shortening of APD probably via blocking stretch-activated ion channels.