Single K+ channel currents of anomalous rectification in cultured rat myotubes.
Single K+ channel currents of anomalous rectification in cultured rat myotubes.
复制标题
培养大鼠肌管中异常整流的单 K 通道电流。
DOI：
10.1073/pnas.78.8.4960
复制
发表时间：
1981
影响因子：
11.1
通讯作者：
Hagiwara,S
中科院分区：
文献类型：
--
作者：
Ohmori,H;Yoshida,S;Hagiwara,S
利用Sigworth和Neher开发的“千兆欧密封”膜片钳技术，在组织培养的大鼠肌管中记录了异常（或内向）整流器的单个K+通道电流。这些单一电流被检测为由于Ba2+阻塞和解除通道阻塞而产生的电流波动。单通道电导由单一电流幅值与膜电位线性关系的斜率得到。当外源溶液含有155 mM K+时，单通道电导为10.4 +/- 2.6 pS （+/- SD; n = 6）。该值与阻滞离子浓度无关，但随着外部K+浓度的增加而增加。单一电流的行为与Ba2+对异常整流器宏观K+电流的阻塞动力学的预期一致。通道的密度可能很小，甚至可能小于1/微米2。
The currents through single K+ channels of the anomalous (or inward) rectifier were recorded in tissue cultured rat myotubes by using the "gigohm seal" patch clamp technique developed by Sigworth and Neher. These unitary currents were detected as current fluctuations due to the blocking and unblocking of channels by Ba2+. The single-channel conductance was obtained from the slope of the linear relationship between unitary current amplitude and membrane potential. When the external solution contained 155 mM K+, the single-channel conductance was 10.4 +/- 2.6 pS (+/- SD; n = 6). This value was independent of the the concentration of blocking ions but increased with increasing external K+ concentration. The behavior of the unitary current agreed with that expected from the blocking kinetics of Ba2+ on the macroscopic K+ current of the anomalous rectifier. The density of the channel is likely to be small and may even be less than 1/micrometers 2.