Ehrenstein G, Gilbert D L
Biophys J. 1966 Sep;6(5):553-66. doi: 10.1016/S0006-3495(66)86677-8.
A slow potassium inactivation i.e. decrease of conductance when the inside of the membrane is made more positive with respect to the outside, has been observed for the squid axon. The conductance-potential curve is sigmoid shaped, and the ratio between maximum and minimum potassium conductance is at least 3. The time constant for the change of potassium conductance with potential is independent of the concentration of potassium in the external solution, but dependent upon potential and temperature. At 9 degrees C and at the normal sea water resting potential, the time constant is 11 sec. For lower temperature or more depolarizing potentials, the time constant is greater. The inactivation can be described by modifying the Hodgkin-Huxley equation for potassium current, using one additional parameter. The modified equation is similar in form to the Hodgkin-Huxley equation for sodium current, suggesting that the mechanism for the passive transport of potassium through the axon membrane is similar to that for sodium.
对于枪乌贼轴突，已观察到一种缓慢的钾离子失活现象，即当膜内侧相对于外侧变得更正时，电导降低。电导-电位曲线呈S形，最大钾电导与最小钾电导之比至少为3。钾电导随电位变化的时间常数与外部溶液中钾的浓度无关，但取决于电位和温度。在9摄氏度和正常海水静息电位下，时间常数为11秒。对于更低的温度或更去极化的电位，时间常数更大。这种失活可以通过修改用于钾电流的霍奇金-赫胥黎方程来描述，使用一个额外的参数。修改后的方程在形式上类似于用于钠电流的霍奇金-赫胥黎方程，这表明钾通过轴突膜的被动运输机制与钠相似。
