一种筛选抗心律失常药物新模型的建立

Construction of a new model for screening antiarrhythmic drugs

目的 建立一种细胞水平的心律失常模型 ,以用于抗心律失常药物的筛选和评价。方法 酶解法分离单个大鼠心室肌细胞 ,在细胞水平给予传统诱发心律失常药物乌头碱 ,应用膜片钳技术观察记录应用乌头碱后心肌动作电位时程 (APD)、钠电流 (INa)、L 型钙电流 (ICa L)、内向整流钾电流(IK1)及瞬时外向钾电流 (Ito)的变化。结果 应用乌头碱 1μmol·L-1使大鼠单个心室肌细胞 90 %复极化动作电位时程(APD90 )从给药前的 ( 15 0 2 3± 7 0 2 )ms延长至 ( 2 3 6 0 3±2 3 2 2 )ms(n =8,P <0 0 1)。应用奎尼丁 10 μmol·L-1后动作电位时程延长与乌头碱组比较 ,APD90 进一步延长 (n =6,P <0 0 5 ) ,但应用维拉帕米 10 μmol·L-1后被乌头碱延长的APD恢复近于正常 ,在乌头碱的作用下 ,除极电压为 0mV时ICa L从 ( 72 7 9± 178 0 ) pA增加至 ( 10 82 1± 2 2 2 2 ) pA(n =6,P <0 0 1) ;钠电流 (INa)在 - 5 0mV刺激电压下从( 2 5 4± 5 5 3 ) pA增加至 ( 45 3 0 2± 475 1) pA(n =4,P <0 0 5 ) ;IK1在 - 12 0mV的刺激电压下 ,Ik1的内向成分从( 2 0 0 7 1± 3 5 9 3 ) pA增加至 ( 2 3 17 7± 40 1 8)pA(n =10 ,P <0 0 1) ;奎尼丁、维拉帕米对乌头碱诱发的钠电流和钙电流增加有抑制的作用。结论 乌头碱使?

AIM To construct a new model based on cellular level in order to screen and evaluate effect of antiarrhythmic drugs. METHODS Enzymatic dissociation was used to get single rat ventricular myocytes and whole cell patch-clamp techniques were used to record action potential(AP) and ionic currents such as sodium currents(I Na),L-type calcium currents(I Ca-L), Inward rectifier potassium currents(I K1) and transient outward potassium currents(I to).RESULTS Aconitine 1 μmol·L -1 prolonged the action potential duration at repolarization of 50% and 90%. The APD 90 was significantly prolonged from (150 23±7 02) ms to (236 03±23 22) ms(n=8,P<0 01).This prolongation was not recovered and further prolonged compared with aconitine 10 minutes after quinidine 10 micromole was administration (n=6,P<0 05), whereas it was reversed by application of verapamil 10 micromole. Aconitine can increase inward sodium and L-type calcium current which could be inhibited by administration of verapamil. CONCLUSION The single cellular action potential and many kinds of ionic currents were changed after exposure to aconitine. Any kinds of drugs which has antiarrhythmic effect may show treatment effects on the model. It provides a simple way to divide the types of antiarrhythmic drugs. So it is a stable and liable method to screen and evaluate antiarrhythmic drugs.