Reverdin E C, Weingart R
Department of Physiology, University of Berne, Switzerland.
Am J Physiol. 1988 Feb;254(2 Pt 1):C226-34. doi: 10.1152/ajpcell.1988.254.2.C226.
Cell pairs isolated from adult rat liver were used to study the electrical properties of gap junctions. Each cell of a cell pair was connected to a suction pipette so as to enable whole cell tight-seal recording. A double voltage-clamp approach was adopted to control the voltage gradient across the gap junction and measure the transjunctional current. The current-voltage relationship of the gap junctional membrane was linear over the voltage range tested (+/- 50 m V). Under control conditions, the resistance of the gap junction, rj, was 15 M omega (n = 27; range, 4.6 to 45.8 M omega), corresponding to a conductance gj of 67 nS. rj was insensitive to the nonjunctional membrane potential, Vm (voltage range,-90 m V to + 40 m V). There was no indication of a time-dependent gating of rj (time range, 20 ms to 10 s). Dialysis with 1 mM CaCl2 produced irreversible electrical uncoupling without affecting the linearity of the relationship Vj/Ij.
从成年大鼠肝脏分离出的细胞对用于研究间隙连接的电特性。细胞对中的每个细胞都连接到一个吸管，以便进行全细胞紧密封接记录。采用双电压钳方法来控制跨间隙连接的电压梯度并测量跨连接电流。在测试的电压范围内（±50 mV），间隙连接膜的电流-电压关系呈线性。在对照条件下，间隙连接的电阻rj为15 MΩ（n = 27；范围为4.6至45.8 MΩ），对应于67 nS的电导gj。rj对非连接膜电位Vm（电压范围为-90 mV至+40 mV）不敏感。没有迹象表明rj存在时间依赖性门控（时间范围为20 ms至10 s）。用1 mM CaCl2进行透析会产生不可逆的电去偶联，而不会影响Vj/Ij关系的线性。
