Na(+)-activated K+ channels: a new family of large-conductance ion channels

Trends Neurosci. 1994 Apr;17(4):155-60. doi: 10.1016/0166-2236(94)90093-0.


Sodium-activated K+ channels (IK(Na)) are a class of large-conductance ion channels expressed in several populations of vertebrate neurons, mammalian cardiac myocytes and Xenopus oocytes. These channels are activated by the binding of Na+ to sites located on the cytoplasmic face of the channel. The physiological functions of IK(Na) channels have been difficult to ascertain, in part because their activation typically requires Na+ concentrations considerably higher than those that are normally present in the cytosol. However, there is now evidence suggesting that IK(Na) can play a role in the regulation of neuronal excitability, the modulation of the action-potential waveform, and the responses of excitable cells to hypoxia and ischemia.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Animals
  • Cations / pharmacology
  • Ion Channel Gating / drug effects
  • Ion Channel Gating / physiology*
  • Neurons / drug effects
  • Neurons / physiology
  • Potassium Channels / classification*
  • Potassium Channels / drug effects
  • Potassium Channels / physiology
  • Signal Transduction / drug effects
  • Signal Transduction / physiology
  • Sodium / physiology*
  • Tetrodotoxin / pharmacology
  • Vertebrates / physiology


  • Cations
  • Potassium Channels
  • Tetrodotoxin
  • Sodium