Weingart R, Bukauskas F F
Department of Physiology, University of Berne, Switzerland.
Pflugers Arch. 1993 Jul;424(2):192-4. doi: 10.1007/BF00374611.
Formation of gap junction coupled cell pairs was used to assess the basic properties of single gap junction channels. For this purpose, two single cells (clone C6/36, derived from larvae of an insect, Aedes albopictus) were maneuvered against each other to provoke gap junction channel insertion. Intercellular current flow was measured with a dual voltage-clamp method. Utilizing this approach, we were able to demonstrate that gap junction channels, after formation, do not close completely upon application of a transjunctional voltage gradient, Vj. Instead, they exhibit a residual conductance, gamma j(residual). On average, gamma j(residual) was 64 +/- 4 pS (n = 40). This corresponds to about 1/6 of the conductance of a fully open channel. The existence of gamma j(residual) explains the observation that the conductance of the entire gap junction, gj, decreases only partially at large Vj.
使用形成间隙连接耦合细胞对的方法来评估单个间隙连接通道的基本特性。为此，将两个单细胞（克隆C6/36，源自白纹伊蚊幼虫）相互操作以促使间隙连接通道插入。采用双电压钳法测量细胞间电流。利用这种方法，我们能够证明间隙连接通道形成后，在施加跨连接电压梯度Vj时不会完全关闭。相反，它们表现出残余电导γj（残余）。平均而言，γj（残余）为64±4 pS（n = 40）。这大约相当于完全开放通道电导的1/6。γj（残余）的存在解释了在大Vj时整个间隙连接的电导gj仅部分降低的现象。
