Formation of gap junctions by treatment in vitro with potassium conductance blockers.
Formation of gap junctions by treatment in vitro with potassium conductance blockers.
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DOI：
10.1083/jcb.78.2.338
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发表时间：
1978-08
影响因子：
7.8
通讯作者：
Daniel, E E
中科院分区：
文献类型：
--
作者：
Kannan, M S;Daniel, E E
在体外培养的犬气管平滑肌薄片中经常能看到缝隙连接。在体外暴露于两种钾离子电导阻滞剂——四乙铵（TEA）和4 - 氨基吡啶（4 - AP）中的任何一种时，其数量都会增加，同时肌肉变得有机械活性，出现自发收缩。这种平滑肌中缝隙连接的存在可能为细胞间耦合提供一个基础，并且在TEA和4 - AP处理后它们数量的增加可以解释细胞间连接电阻的降低，有助于增加空间常数。然而，缝隙连接数量的增加并不足以将气管平滑肌的行为从多单位型转变为单单位型。在洗去4 - AP后，尽管4 - AP的收缩作用被阿托品抑制，但数量增加的缝隙连接仍然存在，而4 - AP的洗去会导致自发收缩受到抑制。缝隙连接形成的快速诱导并不依赖于蛋白质的从头合成。缝隙连接数量可被化学试剂增加这一事实对其形成的控制具有重要意义，并为分析它们在细胞间耦合中的作用提供了一种工具。
Gap junctions were regularly seen in thin sections of canine tracheal smooth muscle incubated in vitro. Their number was increased in tissued exposed in vitro to either of two potassium conductance blockers, tetraethylammonium (TEA) and 4-aminopyridine (4-AP), and at the same time the muscles became mechanically active, with spontaneous contractions. The presence of gap junctions in this smooth muscle may provide one basis for cell-to-cell coupling, and their increase after TEA- and 4-AP-treatment could account for a decreased junctional resistance between cells, contributing to a longer space constant. However, an increase in gap junctions was not sufficient to change the behavior of trachealis smooth muscle from multiunit to single-unit type. Gap junctions in increased numbers persisted after washout of 4- AP, which caused inhibition of spontaneous contractions, and despite inhibition of the contractile effects of 4-AP by atropine. The rapid induction of gap junction formation was not dependent on de novo synthesis of protein. The fact that the number of gap junctions can be increased by chemical agents has important implications for control of their formation and provides a tool for analysis fo their role in cell- to-cell coupling.