Both membrane stretch and fatty acids directly activate large conductance Ca2+-activated K+ channels in vascular smooth muscle cells

Michael T. Kirber, Richard W. Ordway, Lucie H. Clapp, John V. Walsh, Joshua J. Singer

Research output: Contribution to journalArticle

176 Scopus citations

Abstract

Large conductance Ca2+-activated K+ channels in rabbit pulmonary artery smooth muscle cells are activated by membrane stretch and by arachidonic acid and other fatty acids. Activation by stretch appears to occur by a direct effect of stretch on the channel itself or a closely associated component. In excised inside-out patches stretch activation was seen under conditions which precluded possible mechanisms involving cytosolic factors, release of Ca2+ from intracellular stores, or stretch induced transmembrane flux of Ca2+ or other ions potentially capable or activating the channel, Fatty acids also directly activate this channel. Like stretch activation, fatty acid activation occurs in excised inside-out patches in the absence of cytosolic constituents. Moreover, the channel is activated by fatty acids which, unlike arachidonic acid, are not substrates for the cyclo-oxygenase or lypoxygenase pathways, indicating that oxygenated metabolites do not mediate the response. Thus, four distinct types of stimuli (cytosolic Ca2+, membrane potential, membrane stretch, and fatty acids) can directly affect the activity of this channel.

Original languageEnglish (US)
Pages (from-to)24-28
Number of pages5
JournalFEBS Letters
Volume297
Issue number1-2
DOIs
StatePublished - Feb 3 1992

All Science Journal Classification (ASJC) codes

  • Biophysics
  • Structural Biology
  • Biochemistry
  • Molecular Biology
  • Genetics
  • Cell Biology

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