Taura T, Teshima R, Murata T
Ophthalmic Res. 1983;15(6):307-13. doi: 10.1159/000265277.
Measurement of membrane potentials in isolated frog lens fibers was made by means of intracellular microelectrode techniques. The membrane potentials of lens fibers were depolarized to various degrees after exposure to diamide, an -SH inhibitor. When the degree of diamide-induced depolarization was less than 20 mV, the membrane potentials almost fully recovered to the control level within 12 h after immersion in a Ringer's solution containing dithiothreitol (DTT), a -SH protector. A similar tendency was also recognized in some lenses (57%) whose depolarization was 30 mV. When the degree of depolarization was 40 mV, the membrane potentials further depolarized in all cases tested in spite of treatment with DTT. From this study, it is considered that frog lens fibers could not recover their function if the damage was so severe as to produce a membrane depolarization of more 40 mV. Determination of ionic concentrations in lens fibers revealed a highly significant correlation between the degree of diamide-induced depolarization and changes in concentration ratio of Na+/K+.
采用细胞内微电极技术对分离的青蛙晶状体纤维的膜电位进行测量。在暴露于二酰胺（一种巯基抑制剂）后，晶状体纤维的膜电位出现不同程度的去极化。当二酰胺诱导的去极化程度小于20 mV时，在浸入含有二硫苏糖醇（DTT，一种巯基保护剂）的林格氏溶液中12小时内，膜电位几乎完全恢复到对照水平。在一些去极化程度为30 mV的晶状体（57%）中也观察到类似趋势。当去极化程度为40 mV时，尽管用DTT处理，在所有测试的情况下膜电位仍进一步去极化。从这项研究可以认为，如果损伤严重到产生超过40 mV的膜去极化，青蛙晶状体纤维就无法恢复其功能。对晶状体纤维中离子浓度的测定表明，二酰胺诱导的去极化程度与Na+/K+浓度比的变化之间存在高度显著的相关性。
