【摘要】 目的观察氟喹诺酮类抗菌药安妥沙星(ATFX)对豚鼠心肌动作电位的影响。方法微电极记录豚鼠右心室乳头肌动作电位。结果(1)当刺激周长为1000 ms时,各浓度的司帕沙星(SPX)均显著性延长APD50和APD90(P<0.05),而左氧氟沙星(LVFX)和ATFX在浓度超过10μmol/L时明显延长APD90(P<0.05),且ATFX延长APD90的效应明显弱于LVFX和SPX。(2)用E-4031阻断IKr电流,ATFX延长APD90的效应部分被逆转;而用Chro-manol 293B阻断IKs电流,ATFX延长APD90的效应仍存在(P<0.05);但E-4031和Chromanol 293B共同作用阻断IK电流后,ATFX延长APD90的效应可明显被逆转。(3)在药物浓度为10μmol/L时,随着刺激周长的延长,3种药物虽呈不同程度延长APD90,但相差无显著性,提示药物引起的APD延长无明显的频率依赖性。结论ATFX可能通过抑制IKr电流而延长APD,但其效应明显弱于LVFX和SPX。更多还原

【Abstract】 Objective To examine the effects of a new fluoroquinolone antibacterial agents,antofloxacin on cardiac action potentials.Methods Action potentials were recorded from isolated papillary muscles of guinea pig right ventricles by using conventional microelectrode techniques.Results(1)Under the condition of basic cycle length of 1000 ms,both APD50 and APD90 were prolonged by sparfloxacin at any used concentrations.While,the similar effects can only be observed when the concentrations of levofloxacin or antofloxacin were over 10 μmol/L.(2)The prolongation of APD90 induced by 10 μmol/L antofloxacin was abolished by pretreatment with E-4031 or by E-4031 plus Chromanol 293B,but no obvious change by pretreatment with Chromanol 293B alone.(3)With the basic cycle length increased,the prolongation of APD90 caused by those three drugs were increased,but the difference as compare to control was not significant.Conclusion Antofloxacin prolonged cardiac APD through inhibition of IKr with less potency than LVFX and SPX.更多还原