Li J M, Cui G Y, Liu D J, Cui H, Chang T H, Wang Y P, Zhang K Y
Department of Pharmacology, China Medical University, Shenyang, China.
Zhongguo Yao Li Xue Bao. 1998 Jan;19(1):24-6.
To study the effects of N-methyl berbamine (NMB) on the delayed outward potassium currents (Ik) in isolated rat hepatocytes.
With patch-clamp techniques and whole-cell recording method, holding potential -50 mV, command potential +30 to +140 mV, duration 900 ms.
NMB reduced Ik in a concentration-dependent manner. When the concentrations of NMB were 20, 50, 400 nmol.L-1 and 50 mumol.L-1, the amplitude values of Ik were decreased 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 nA (P < 0.01) from 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 of control, respectively. The inhibitory rates were 10%, 15%, 37%, and 51%, respectively.
NMB was a K+ channel inhibitor.
研究N-甲基小檗胺（NMB）对离体大鼠肝细胞延迟外向钾电流（Ik）的影响。
采用膜片钳技术和全细胞记录方法，钳制电位为-50mV，指令电位为+30至+140mV，持续时间900ms。
NMB以浓度依赖性方式降低Ik。当NMB浓度分别为20、50、400nmol·L-1和50μmol·L-1时，Ik的幅值从对照的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分别降至3.6±0.4（P>0.05）、2.1±1.6（P>0.05）、3.7±1.6（P<0.05）、2.3±1.3nA（P<０.01）。抑制率分别为10%、15%、37%和51%。
NMB是一种钾通道抑制剂。
