ELECTRICAL COUPLING BETWEEN CELLS IN ISLETS OF LANGERHANS FROM MOUSE
ELECTRICAL COUPLING BETWEEN CELLS IN ISLETS OF LANGERHANS FROM MOUSE
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DOI：
10.1007/bf01871095
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发表时间：
1984-01-01
影响因子：
2.4
通讯作者：
ROJAS, E
中科院分区：
文献类型：
--
作者：
EDDLESTONE, GT;GONCALVES, A;ROJAS, E
用两个微电极同时测量小鼠胰岛细胞对的膜电位。在存在浓度在5.6和22.2mM之间的葡萄糖的情况下，将电流i注入到细胞1中引起该细胞中的膜电位变化V1，并且如果第二微电极< 35 μ m远，则在第二刺穿的细胞2中引起膜电位变化V2。在胰岛细胞之间显然存在电耦合，并且胰岛组织内耦合比的空间常数显然是几个β-1的量级。细胞直径电流-膜电位曲线i-V1和i-V2非常相似。通过交换微电极的作用，没有证据整流的电流通过细胞间的pathways被发现。去除葡萄糖引起的耦合比V2/V1的迅速下降。在稳态条件下，耦合比随葡萄糖浓度在0-22 mM的范围内增加。连接和非连接膜的等效电阻的值进行了估计，并随葡萄糖浓度的变化。外部应用的线粒体阻滞剂诱导的交界电阻可能介导的细胞内Ca 2+的增加适度增加。
Two microelectrodes were used to measure membrane potentials simultaneously in pairs of mouse pancreatic islet cells. In the presence of glucose at concentrations between 5.6 and 22.2 mM, injection of current i into cell 1 caused a membrane potential change in this cell, V1, and, provided the 2nd microelectrode was < 35 .mu.m away, in a 2nd impaled cell 2, V2. There evidently is electrical coupling between islet cells and the space constant of the coupling ratio within the islet tissue is apparently of the order of a few .beta.-cell diameters. The current-membrane potential curves i-V1 and i-V2 are very similar. By exchange of the roles of the microelectrodes, no evidence of rectification of the current through the intercellular pathways was found. Removal of glucose caused a rapid decrease in the coupling ratio V2/V1. In steady-state conditions, the coupling ratio increased with the concentration of glucose in the range from 0-22 mM. Values of the equivalent resistance of the junctional and nonjunctional membranes were estimated and changed with the concentration of glucose. Externally applied mitochondrial blockers induced a moderate increase in the junctional resistance possibly mediated by an increase in intracellular Ca2+.