ATP inhibits smooth muscle Ca2+-activated K+ channels

C. H. Gelband, S. D. Silberberg, K. Groschner, C. Van Breemen

Research output: Contribution to journalArticlepeer-review

30 Scopus citations


There has been much recent interest in the roles played by smooth-muscle K+ channels in protecting cells against ischemic and anoxic insults and in therapeutic vaso- and bronchodilation (Buckingham 1990; Longmore and Weston 1990). A K+ channel, which is uniquely sensitive to cytoplasmic ATP (K(ATP)), has been identified as a likely candidate for mediating these important functions (Standen et al. 1989). We now show, by using electrophysiological techniques in three different types of smooth muscle, that a large-conductance voltage and Ca2+-sensitive channel, otherwise indistinguishable from the large-conductance Ca2+-activated K+ channel (BK channel), is also sensitive to cytoplasmic ATP and cromakalim. ATP, in a dose-dependent manner, decreased the probability of channel opening (P(o) of rabbit aortic, rabbit tracheal and pig coronary artery BK channels with a K(i) of 0.2-0.6 mM. Cromakalim, 10 μM, partially reversed the ATP induced inhibition and increased P(o). Our observations raise the possibility that the ubiquitous BK channel may play a role during pathophysiological events.

Original languageEnglish
Pages (from-to)23-28
Number of pages6
JournalProceedings of the Royal Society B: Biological Sciences
Issue number1303
StatePublished - 1 Jan 1990
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology (all)
  • Immunology and Microbiology (all)
  • Environmental Science (all)
  • Agricultural and Biological Sciences (all)


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