Cardiac gap junction channel activity in embryonic chick ventricle cells.
Cardiac gap junction channel activity in embryonic chick ventricle cells.
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胚胎鸡心室细胞中的心脏间隙连接通道活性。
DOI：
10.1152/ajpheart.1988.254.1.h170
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
DeHaan,RL
中科院分区：
文献类型：
--
作者：
Veenstra,RD;DeHaan,RL
用双全细胞膜片钳技术记录了出生7天的鸡胚心室肌细胞对的缝隙连接通道电流。结电导（Gj）是可变的，从一个制备到下一个，范围从0.15到35.0 nS。主连接通道的单通道电导（gamma j）为166 +/- 51 pS，与Gj无关;在有利记录中还观察到60-80 pS的第二个电导水平。从关闭状态到打开状态的转换时间为285 +/-153微秒，其中一些缓慢的转换持续1-5毫秒。Gj可以由接头中的活动通道的数量（N）、通道的平均开放状态概率（Po）通道活性不受细胞膜电位或跨接电位的影响。Po和Gj可逆地降低到低水平的1-辛醇或升高[蔡]，而γ j是不变的这些代理。60-80 pS的电导机制是辛醇和钙抗性的，但尚不清楚这是否代表主通道的亚电导水平或单独的一类较小的通道。
We have recorded single-gap junction-channel currents from pairs of 7-day chick embryo ventricle cells, using the double whole cell patch-clamp technique. Junctional conductance (Gj) was variable from one preparation to the next, ranging from 0.15 to 35.0 nS. Single-channel conductance (gamma j) of the main junctional channel was 166 +/- 51 pS and was independent of Gj; a second conductance level of 60–80 pS was also seen in favorable records. The transition time from the closed to the open state was 285 +/- 153 microseconds, with some slow transitions lasting 1–5 ms. Channels opened and closed stochastically; Gj could be defined by the product of the number of active channels in the junction (N), the mean open-state probability (Po) of the channels, and gamma j. Channel activity was unaffected by cell membrane potential or by transjunctional potential. Po and Gj were reversibly reduced to low levels by 1-octanol or by elevated [Cai], whereas gamma j was unchanged by these agents. The 60–80 pS conductance mechanism was octanol- and Ca-resistant, but it is not clear whether this represents a subconductance level of the main channel or a separate class of smaller channels.