The Role of TASK-Like K+ Channels in Oxygen Sensing in the Carotid Body

Keith J. Buckler, Beatrice A. Williams, Rodrigo Varas Orozco, Christopher N. Wyatt

Research output: Chapter in Book/Report/Conference proceedingChapter

Abstract

The carotid body plays an important role in initiating protective responses to hypoxemia. The primary oxygen sensing cells are the glomus or type 1 cells. Hypoxia evokes the secretion of neurotransmitters from these cells which then excite afferent nerves. This response is mediated via membrane depolarization and voltage-gated Ca2+ entry. Studies from this laboratory have revealed that membrane depolarization in response to hypoxia is primarily the result of inhibition of background K+ channels which show strong similarities to the acid sensitive tandem-P-domain K+ channels TASK-1 and TASK- 3. The background K+ channels of type-1 cells are also very sensitive to inhibition of mitochondrial energy metabolism and, in excised patches, appear to be directly activated by ATP. Thus these TASK-like background channels would appear to confer the ability to sense changes in oxygen levels, pH and metabolism upon the type 1 cell. The key issue of whether the effects of hypoxia are mediated through changes in metabolism remains unanswered but the effects of inhibition of mitochondrial energy metabolism and of hypoxia upon background K+ channels is mutually exclusive suggesting that there is a close link between metabolism and oxygen sensing in the type 1 cell.
Original languageEnglish
Title of host publicationSignalling Pathways in Acute Oxygen Sensing
Subtitle of host publicationNovartis Foundation Symposium 272
Publisherwiley
Pages73-94
Number of pages22
Volume272
ISBN (Electronic)9780470035009
ISBN (Print)0470014571, 9780470014578
DOIs
StatePublished - Oct 7 2008

ASJC Scopus Subject Areas

  • General Biochemistry,Genetics and Molecular Biology

Keywords

  • Background K channels and oxygen sensing in type 1 cells
  • Hypoxia and metabolism
  • Metabolism and oxygen sensing
  • TASK-like background K channels
  • Whole cell voltage-clamp technique

Disciplines

  • Cellular and Molecular Physiology

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