Kukita F, Yamagishi S
Jpn J Physiol. 1979;29(6):669-81. doi: 10.2170/jjphysiol.29.669.
Excitability of intracellularly perfused squid giant axons was maintained in hypotonic solutions (down to 300 mOSM) and in hypertonic solutions (up to about 10 OSM), when osmolalities of internal and external solutions were adjusted to be equal with glycerol, glucose, or sucrose. Molar concentrations of ions were kept constant during one series of experiments. The resting potential and the amplitude of the action potential did not change in both hypotonic and hypertonic solutions. With reduction of osmolality, the duration of action potential decreased and the maximum rate of rise and conduction velocity increased. By raising osmolality, the duration was prolonged and the maximum rate of rise and the conduction velocity decreased. Effects of osmolality change were almost reversible. However, these effects were not directly related to the osmolality change but seemed to be related to the viscosity change of the solutions. When the osmolality of external solution was raised with NaCl (up to 2.6 M NaCl), the overshoot increased in porportion to the logarithm of the NaCl concentration. The slope of increase was about 50 mV/decade. However, the resting potential showed little change. With increase of the NaCl concentration, the duration of the action potential increased.
当用甘油、葡萄糖或蔗糖将细胞内灌注的枪乌贼巨大轴突的细胞内液和细胞外液渗透压调节至相等时，其兴奋性在低渗溶液（低至300毫渗量）和高渗溶液（高达约10渗量）中均可维持。在一系列实验过程中，离子的摩尔浓度保持恒定。在低渗和高渗溶液中，静息电位和动作电位的幅度均未发生变化。随着渗透压降低，动作电位的持续时间缩短，最大上升速率和传导速度增加。随着渗透压升高，动作电位持续时间延长，最大上升速率和传导速度降低。渗透压变化的影响几乎是可逆的。然而，这些影响并非直接与渗透压变化相关，而是似乎与溶液的粘度变化有关。当用氯化钠升高细胞外液渗透压（高达2.6 M氯化钠）时，动作电位的超射幅度与氯化钠浓度的对数成正比增加。增加的斜率约为50 mV/十倍浓度变化。然而，静息电位几乎没有变化。随着氯化钠浓度的增加，动作电位的持续时间延长。
