大鼠肝细胞外向钾电流的实验研究

The Outward Potassium Current in Isolated rat Hepatocytes

目的：研究大鼠肝细胞上外向钾电流。方法：全细胞膜片钳制方法观察大鼠肝细胞延迟外向钾电流（Ｉｋ）和瞬间外向钾电流（Ｉｔｏ）及去甲肾上腺素等对Ｉｋ的影响。结果：正常细胞外液条件下，大鼠肝细胞在保持电位－５０ｍＶ，＋１４０ｍＶ刺激电压时Ｉｋ为（２．８５±１．２１）ｎＡ。应用改变保持电位（－８０ｍＶ和－３０ｍＶ）的方法。初步区分Ｉｔｏ和Ｉｋ，Ｉｔｏ值为（１．３９±０．５８）ｎＡ。结论：去甲肾上腺素明显降低Ｉｋ。

Objective: The purpose of this paper was to investigate the outward potassium currents in rat hepatocytes. Methods: We used whole cell patch clamp technique to observe the effect of noradrenaline and other reagents on the delayed outward potassium current (I k) and the transient outward potassium current (I to ) in isolated rat hepatocytes. Results: The magnitude of I k was (2.85±1.21) nA at a command potential of +140 mV from a holding potential of -50 mV. With the change of holding potential (-80 mV and -30 mV), I to and I k were preliminarily discriminated from each other. The magnitude of I to was (1.39±0.58) nA. Conclusions: Noradrenaline decreased I k distinctly. Isoprenaline and acetylcholine showed no effect on I k in isolated rat hepatocytes.