Ionic dependence of reversal voltage of the light response in Limulus ventral photoreceptors.
Ionic dependence of reversal voltage of the light response in Limulus ventral photoreceptors.
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DOI：
10.1085/jgp.63.3.337
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发表时间：
1974-03
期刊：
影响因子：
--
通讯作者：
Mote MI
中科院分区：
文献类型：
--
作者：
Brown JE;Mote MI
使用电压钳（静息电位下的保持电压）测量的光诱导电流在浴溶液中的钠离子Nao被Tris、胆碱或Li替代时或NaCl被蔗糖替代时衰减。用蔗糖代替NaCl后，光响应的反转电压V rev变得更负。在这种情况下，在Nao = 425 mM附近，V rev与log Nao的斜率约为55 mV/十倍Nao增加（13个细胞的平均值）。斜率在较低的Nao值处减小。胆碱不是不渗透的，部分替代Na; V rev与log Nao的斜率为20 mV/decade（三个细胞的平均值）。当Na被Li取代时，V rev不改变。在浴浓度的Ca，Mg，Cl，或K的减少不影响V的转速。当Nao = 212 mM，V的转速变得更加积极，当Ko增加。因此，光诱导膜对Na和可能对K的渗透性的变化。
The light-induced current as measured using a voltage clamp (holding voltage at resting potential) is attenuated when sodium ions in the bathing solution, Nao, are replaced by Tris, choline, or Li or when NaCl is replaced by sucrose. After replacement of NaCl by sucrose, the reversal voltage, V rev, for the light response becomes more negative. In this case, the slope of the V rev vs. log Nao near Nao = 425 mM is approximately 55 mV/decade increase of Nao (mean for 13 cells). The slope decreases at lower values of Nao. Choline is not impermeant and partially substitutes for Na; the slope of V rev vs. log Nao is 20 mV/decade (mean for three cells). V rev does not change when Na is replaced by Li. Decreases in the bath concentrations of Ca, Mg, Cl, or K do not affect V rev. When Nao = 212 mM, V rev becomes more positive when Ko is increased. Thus, light induces a change in membrane permeability to Na and probably also to K.