某些离子对蛔虫肌肉膜电位的影响
INFLUENCE OF SOME IONS ON THE MEMBRANE POTENTIAL OF ASCARIS MUSCLE.
作者信息
DELCASTILLO J, DEMELLO W C, MORALES T
出版信息
J Gen Physiol. 1964 Sep;48(1):129-40. doi: 10.1085/jgp.48.1.129.
The influence of several ions on the membrane potential of the somatic muscle of Ascaris has been investigated by changing their concentration in the surrounding solution. When K is increased at the expense of Na leaving Cl constant, the membrane potential is first seen to increase. K higher than 45 mM reduces the membrane potential with a slope of 23 mv for a tenfold change in K. However, when K is increased keeping Na and Cl low and constant, the line relating the membrane potential with log K has a slope of almost 50 mv. If Cl is reduced in the absence of external Na, after the K is increased to 45 mM, the membrane potential decreases with a slope of 59 mv per tenfold change in Cl in close agreement with the Nernst equation. If Cl(-) is replaced by SO(4) (2-), a depolarization is produced, while chloride replacement by NO(3) (-), Br(-), and I(-) results in a hyperpolarization of the membrane. Removal of the external Na(+) ions increases the average membrane potential by 17 mv.
通过改变蛔虫体肌周围溶液中几种离子的浓度，研究了它们对蛔虫体肌膜电位的影响。当以降低Na为代价增加K，而使Cl保持恒定时，首先会观察到膜电位升高。当K高于45 mM时，K每变化10倍，膜电位以23 mV的斜率降低。然而，当在保持Na和Cl低且恒定的情况下增加K时，膜电位与log K的关系曲线斜率接近50 mV。如果在没有外部Na的情况下降低Cl，在将K增加到45 mM之后，膜电位随Cl每变化10倍以59 mV的斜率降低，这与能斯特方程高度吻合。如果用SO(4) (2-)取代Cl(-)，会产生去极化，而用NO(3) (-)、Br(-)和I(-)取代氯离子会导致膜超极化。去除外部Na(+)离子会使平均膜电位增加17 mV。
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