藤壶光感受器内的细胞内钠、钾和氯活性。
Intracellular Na+, K+, and C1- activities in Balanus photoreceptors.
作者信息
Brown H M
出版信息
J Gen Physiol. 1976 Sep;68(3):281-96. doi: 10.1085/jgp.68.3.281.
Ion-sensitive microelectrodes were used to measure intracellular activities (aix) of Na+, K+, and C-1 in Balanus photoreceptors. Average values of aiNa, aiK, and aiCl were 28 mM, 120 mM, and 65 mM, respectively. Equilibrium potentials calculated from these average values were: Na+ +64 mV, K+ - 77 mV, and and Cl- -42 mV; ther average value of the resting potential for all cells examined was -41 mV. Long exposure to intense illumination produced measurable increases in aiNa. Classical Na+ - K+ reciprocal dilution experiments were analyzed with and without observed changes in aiK. As aoK was increased, the membrane depolarized, and aiK increased. Better agreement was found between the membrane potential and the directly determined EK than expected from the standard relation between Em and aoK. The latter produced pNa:pK estimates of the resting photoreceptor membrane that were higher than estimates based on data from the ion electrodes. Generally, Em was more negative than EK as aoK was increased. This is consistent with a significant chloride permeability in the dark-adapted photoreceptor.
使用离子敏感微电极测量藤壶光感受器中Na⁺、K⁺和Cl⁻的细胞内活性（aix）。aiNa、aiK和aiCl的平均值分别为28 mM、120 mM和65 mM。根据这些平均值计算出的平衡电位为：Na⁺ +64 mV、K⁺ -77 mV和Cl⁻ -42 mV；所有检测细胞的静息电位平均值为-41 mV。长时间暴露于强光下会使aiNa产生可测量的增加。在aiK有无观察到变化的情况下，对经典的Na⁺ - K⁺反向稀释实验进行了分析。随着aoK增加，膜去极化，且aiK增加。发现膜电位与直接测定的EK之间的一致性比根据Em与aoK之间的标准关系预期的更好。后者得出的静息光感受器膜的pNa:pK估计值高于基于离子电极数据的估计值。一般来说，随着aoK增加，Em比EK更负。这与暗适应光感受器中显著的氯离子通透性一致。
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