Na(+)-activated K+ channels: a new family of large-conductance ion channels.
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.
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Program in Neuroscience, Florida State University, Tallahassee 32306-4075.
D000818:Animals; D002412:Cations / Q000494:pharmacology; D015640:Ion Channel Gating / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D015221:Potassium Channels / Q000145:classification* / Q000187:drug effects / Q000502:physiology; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D012964:Sodium / Q000502:physiology*; D013779:Tetrodotoxin / Q000494:pharmacology; D014714:Vertebrates / Q000502:physiology
D002412:Cations; D015221:Potassium Channels; D013779:Tetrodotoxin; D012964:Sodium