Furman R E, Tanaka J C
Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia 19104.
Biophys J. 1988 Feb;53(2):287-92. doi: 10.1016/S0006-3495(88)83091-1.
The influence of patch electrode glass composition on macroscopic IV relations in inside-out patches of the cGMP-activated ion channel from rod photoreceptors was examined for a soda lime glass, a Kovar sealing glass, a borosilicate glass, and several soft lead glasses. In several glasses the shape or magnitude of the currents changed as the concentration of EGTA or EDTA was increased from 200 microM to 10 mM. The changes in IV response suggest that, at low concentrations of chelator, divalent cations are released from the electrode glass and interact with the cGMP-activated channel. Possible mechanisms are discussed to explain the observations, and several comments are made concerning the choice of a glass for patching.
研究了钠钙玻璃、可伐密封玻璃、硼硅酸盐玻璃和几种软铅玻璃的贴片电极玻璃成分对来自视杆光感受器的cGMP激活离子通道的外翻贴片宏观电流-电压关系的影响。在几种玻璃中，当乙二醇双四乙酸（EGTA）或乙二胺四乙酸（EDTA）的浓度从200微摩尔增加到10毫摩尔时，电流的形状或大小发生了变化。电流-电压响应的变化表明，在螯合剂浓度较低时，二价阳离子从电极玻璃中释放出来并与cGMP激活通道相互作用。讨论了解释这些观察结果的可能机制，并对贴片玻璃的选择提出了几点看法。
