目的：研究Ｎ甲基小檗胺（ＮＭＢ）对大鼠肝细胞外向钾电流的影响．方法：应用膜片箝技术和全细胞记录方法，箝制电位－５０ｍＶ，指令电位＋３０至＋１４０ｍＶ，持续时间９００ｍｓ．结果：ＮＭＢ以浓度依赖方式降低外向钾电流．电流幅值在２０，５０，４００ｎｍｏｌ·Ｌ－１和５０μｍｏｌ·Ｌ－１时分别从４４±１０（ｎ＝４），２５±１８（ｎ＝４），５８±２１（ｎ＝５），４６±１３（ｎ＝６）ｎＡ降到３６±０４（Ｐ＞００５），２１±１６（Ｐ＞００５），３７±１６（Ｐ＜００５），２３±１３（Ｐ＜００１）ｎＡ．抑制率分别为１０％，１５％，３７％，５１％．结论：ＮＭＢ是一种钾通道阻断剂． Objective: To study the effect of Nmethyl berbamine (NMB) on the outward potassium current in rat hepatocytes. Methods: Patch clamp technique and whole-cell recording method were used. The clamping potential was -50mV, the command potential was +30 to + 140mV and the duration was 900ms. Results: NMB reduced outward potassium current in a concentration-dependent manner. The current amplitudes ranged from 44 ± 10 (n = 4), 25 ± 18 (n = 4), 55 (superscript nd) to 20,50,400 nmol·L-1 and 50 μmol·L- 8 ± 21 (n = 5), 46 ± 13 (n = 6) nA to 36 ± 04 (P> 005), 21 ± 16 (P > 005), 37 ± 16 (P <005), 23 ± 13 (P <001) nA. Inhibition rates were 10%, 15%, 37%, 51%. Conclusion: NMB is a potassium channel blocker.