CAJ | 학술논문

目的文献报道一些Brugada综合征(Brugada syndrome,BS)患者使用异丙肾上腺素(isoproterenol,Iso)能够减轻ST段抬高,抑制室性心律失常和电风暴的发生.本文对Iso这一作用的细胞电生理机制进行研究.方法酶解法分离兔右心室外膜下心肌(sub-epicardium,Epi)细胞.采用全细胞膜片钳技术记录1 μmol Iso作用前后动作电位(action potential,AP)、L型钙电流(L-type calcium current,ICaL)及短暂外向钾电流(transient outward potassium current,Ito)的变化.结果 ①Iso显著延长动作电位时限(APD);②Iso使ito峰值从(11.4±1.7)pA/pF减少到(6.3±0.5)pA/pF(n=16,P<0.05),使Ito I-V曲线下移,稳态失活曲线左移及失活后恢复曲线右移;③Iso使ICaL峰值从(-6.1±0.6)pA/pF增加到(-8.6±0.9)pA/pF(n=10,P<0.05),使I-V曲线下移.结论 Iso呈电压依赖性抑制,ICaL和增加ICal,延长APD,这可能与Iso能够减轻BS患者ST段抬高,抑制BS患者室性心律失常和电风暴的发生有关.
목적 문헌보도일사Brugada종합정(Brugada syndrome,BS)환자사용이병신상선소(isoproterenol,Iso)능구감경ST단태고,억제실성심률실상화전풍폭적발생.본문대Iso저일작용적세포전생리궤제진행연구.방법 매해법분리토우심실외막하심기(sub-epicardium,Epi)세포.채용전세포막편겸기술기록1 μmol Iso작용전후동작전위(action potential,AP)、L형개전류(L-type calcium current,ICaL)급단잠외향갑전류(transient outward potassium current,Ito)적변화.결과 ①Iso현저연장동작전위시한(APD);②Iso사ito봉치종(11.4±1.7)pA/pF감소도(6.3±0.5)pA/pF(n=16,P<0.05),사Ito I-V곡선하이,은태실활곡선좌이급실활후회복곡선우이;③Iso사ICaL봉치종(-6.1±0.6)pA/pF증가도(-8.6±0.9)pA/pF(n=10,P<0.05),사I-V곡선하이.결론 Iso정전압의뢰성억제,ICaL화증가ICal,연장APD,저가능여Iso능구감경BS환자ST단태고,억제BS환자실성심률실상화전풍폭적발생유관.
Objective To investigate the effect of isoproterenol(Iso)on action potential duration (APD),L-type calcium current(ICaL)andtransient outwardpotassium current(Ito).Methods Single sub-epicardial myocytcs of right ventricle in rabbits were isolated with enzymatic dissociation.The whole-cell patch clamp recording technique was used.Results(1)Iso significantly prolonged APD.(2)Peak Ito decreased from(11.4±1.7)pA/pF to(6.3±0.5)pA/pF(n=16,P<0.05)after using Iso.Iso downshifted the I-V curves of Ito,turned the steady=state inactication curve to left and moved the curve of time recovery from inactivation to risht.(3)Iso increased peak,ICaL from(-6.1±0.6)pA/pF to(-8.6±0.9)pA/pF(n=10,P<0.05)and downshifted the I-V curves.Conclusions Iso could block Ito and augment ICaL in a voltage-dependent manner and prolong APD,which could be the mechanisms of its suppressing ventricular arrhythmia and electrical storm of Brugada syndrome.