Dankó M, Varga E
Acta Physiol Acad Sci Hung. 1980;55(4):319-27.
The dependence of the membrane potential oscillation on extracellular sodium concentration was studied in the frog sartorius muscle. (1) When Na concentration of the Ringer solution was decreased to zero, the membrane potential oscillation cesed and the membrane tended to repolarize. This inhibitory effect was reversible. (2) Tetrodotoxin, 10(-7) g/ml, inhibited the development of membrane potential oscillation or stopped within 2--4 min the membrane potential oscillation already developed, the membrane then became partly repolarized maximum to -72mV. The inhibitory effect of tetrodotoxin was also reversible. (3) When the Na concentration of the Ringer solution was reduced to 60 mM the latency time of the membrane potential oscillation did not change. By further decreasing the Na concentration the latency time increased in a hyperbolic function. In case of 10 mM Na the latency period was 7 times longer than the control. (4) The depolarizing effect of veratrine was linearly related to the logarithm of Na concentration in a range from 10 to 120 mM Na. (5). By decreasing the [Na]c from 120 to 10 mM the frequency of oscillation decreased and the amplitude increased linearly as a function of the logarithm of Na concentration.
在蛙缝匠肌中研究了膜电位振荡对细胞外钠浓度的依赖性。(1) 当任氏液的钠浓度降至零时，膜电位振荡停止，膜趋于复极化。这种抑制作用是可逆的。(2) 10(-7) g/ml的河豚毒素抑制膜电位振荡的发展，或在2 - 4分钟内使已产生的膜电位振荡停止，此时膜部分复极化，最大可达-72mV。河豚毒素的抑制作用也是可逆的。(3) 当任氏液的钠浓度降至60 mM时，膜电位振荡的潜伏期不变。进一步降低钠浓度时，潜伏期呈双曲线函数增加。在钠浓度为10 mM时，潜伏期比对照长7倍。(4) 在10至120 mM钠的范围内，藜芦碱的去极化作用与钠浓度的对数呈线性关系。(5) 通过将[Na]c从120 mM降至10 mM，振荡频率降低，振幅随钠浓度的对数呈线性增加。
