电鳗电板中动作电位发生过程中的钾离子失活与阻抗变化。
Potassium inactivation and impedance changes during spike electrogenesis in eel electroplaques.
作者信息
Ruiz-Manresa F, Ruarte A C, Schwartz T L, Grundfest H
出版信息
J Gen Physiol. 1970 Jan;55(1):33-47. doi: 10.1085/jgp.55.1.33.
Various degrees of pharmacological K inactivation were induced by Cs or Ba in isolated single electroplaques of the electric eel. The resulting changes in K conductance give rise to very different steady-state current-voltage characteristics. They also induce differences in ion dynamics during spike electrogenesis. The dynamic changes were studied by AC bridge methods, registering the changes in impedance in synchrony with the neurally or directly evoked spikes. While spike electrogenesis was virtually unaffected by addition of Cs or Ba, the patterns of impedance changes were very different. The various patterns are accounted for by the changes in the respective current-voltage characteristics. The data constitute new evidence for regarding the electrically excitable component of the reactive membrane as a heterogeneous electrochemical system with separate and independently reactive channels that in the electroplaques are permselective for Na and K, respectively.
在电鳗的分离单电板中，铯（Cs）或钡（Ba）可诱导不同程度的药理学钾（K）失活。由此产生的钾电导变化会导致非常不同的稳态电流-电压特性。它们还会在动作电位产生过程中引起离子动力学差异。通过交流桥法研究动态变化，记录与神经诱发或直接诱发的动作电位同步的阻抗变化。虽然添加铯或钡实际上不影响动作电位的产生，但阻抗变化模式却非常不同。各种模式可由各自电流-电压特性的变化来解释。这些数据为将反应性膜的电可兴奋成分视为一种异质电化学系统提供了新证据，该系统具有分别对钠（Na）和钾具有选择性通透的独立反应通道，在电板中分别对Na和K具有选择通透性。
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