【摘要】 目的　动物实验表明N 甲基小檗胺 (NMB)通过抑制豚鼠心室肌细胞ATP敏感性钾电流和钙电流来发挥抗心律失常和抗心肌缺血作用 ,故进一步研究NMB对人心肌细胞电流的作用。方法　膜片钳制技术全细胞记录模式研究NMB对人心房肌细胞瞬时外向钾电流 (Ito)和延迟整流钾电流 (IK)的作用。结果　指令电位为 +60mV时 ,NMB 0 .1 ,1 ,1 0 μmol·L-1 分别使Ito幅值下降 (1 6± 4) % ,(2 5±4) %和 (49± 3) % ,使IK 幅值下降 (42± 6) % ,(47±7) %和(65± 3) %。结论　NMB对人心房肌细胞Ito和IK 均有抑制作用。更多还原

【Abstract】 AIM The previous studies on animals showed that N -methyl berbamine(NMB) could inhibit ATP sensitive potassium current and Ca 2+ current in ventricular myocytes of guinea pig and play an effective role in arrhythmia and myocardial ischemia. To further elucidate the ionic mechanism of NMB on human heart myocytes, the effects of NMB on transient outward potassium current (I to ) and delayed rectifier potassium current (I K) in human atrial myocytes were investigated. METHODS T he standard whole cell recording method was used. RESULTS At potential of +60 mV, NMB 0.1, 1, 10 μmol·L -1 decreased I to by (16±4)%, (25±4)% and (49±3)%, respectively, and decreased I K by (42±6)%, (47±7)% and (65±3)% (n=5 cells from 4 patients, P <0.05 ), respectively. CONCLUSION NMB depresses I to and I K in human atrial myocytes.更多还原