【摘要】 目的:研究1-（2,6-二甲基苯氧基）-2-（3,4-二甲氧基苯乙氨基）丙烷盐酸盐（DDPH）对心室肌细胞动作电位（AP）、内向整流钾通道电流(I_K1)及延迟整流钾通道电流（I_K）的影响。方法:全细胞膜片箝技术。结果:DDPH 10,100μmol·L^-1使豚鼠心室肌细胞AP时程APD₅₀明显缩短;但DDPH(>1μmol·L^-1)延长APD₉₀。DDPH浓度依赖性地抑制I_K尾电流(I_K·tail),EC₅₀为13.3（11.6.6-16.7）μmol·L^-1。DDPH(>1.0μmol·L^-1)明显抑制I_Kl;同时,DDPH使I_Kl翻转电位向正电位方向移动。结论:DDPH对豚鼠心室肌细胞I_Kl和I_K具有明显的抑制作用。更多还原

【Abstract】 AIM: To study the effects of 1-(2,6-dimethylphenoxy)-2-(3,4-dimethoxyphenyl-ethylamino) propane hydrochlo-ride (DDPH) on action potential (AP), inward rectifier K+ current (IKl), and delayed rectifier K+ current (IK) in isolated guinea pig ventricular myocytes. METHODS: Whole cell patch-clamp recording techniques. RESULTS: DDPH 0.1 - 100 μumol · L-1 decreased 50 % duration of action potential (APD50) concentration-dependently. APD50 was shortened from (493 ± 58) to (262 ±38) ms (n = 7 cells from 5 guinea pigs, P < 0.01) by DDPH 10 μmol· L -1. However, 90 % duration of action potential (APD90) was increased by DDPH ( > 1 μmol · L-1). At high concentration ( > 10 μmol · L-1) DDPH decreased resting membrane potential (RP) and amplitude of action potential (APA). DDPH inhibited tail current of IK(IK·tail) concentration-dependently, 46 % at 10 μmol · L-1 and 78 % at 100 μmol · L-1. EC50 for DDPH inhibiting IK was 13.3 (11.6 - 16.7) μmol·L-1. DDPH also blocked IKl. DDPH at high concentration ( > 10 μmol·L-1) shifted the reverse potential of IKl positively. All the effects of DDPH were reversible after washout. CONCLUSION: DDPH blocked both IKl and IK current in guinea pig ventricular myocytes.更多还原