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Possible involvement of GTP-binding proteins in the deactivation of an inwardly rectifying K+ current in enterocytes isolated from guinea-pig small intestine

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  • Excitable Tissues and Central Nervous Physiology
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Abstract

The possible regulation of guinea pig enterocyte ion channels by GTP-binding proteins has been investigated by using the whole-cell recording mode of the patch-clamp technique and non-hydrolysable analogues of GTP. The main K+ currents in these cells are mediated by inwardly-rectifying K+ channels. Intracellular dialysis with hydrolysis-resistant GTP analogues leads to the deactivation of the inward K+ currents. Non-hydrolysable analogues of ATP or GDP were without effect.The effect occurs after a lag phase of 2 to 7 min, suggesting a multistep mechanism. Cl− currents were not affected by any of the nucleotide analogues. It is suggested that inwardly-rectifying K+ currents are deactivated by a G-protein-dependent process.

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Authors and Affiliations

  1. AFRC Institute of Animal Physiology and Genetics Research, CB2 4AT, Babraham, Cambridge, UK

    F. Fargon & F. V. Sepúlveda

  2. Physiological Laboratory, University of Cambridge, Downing Street, CB2 3EG, Cambridge, UK

    F. Fargon & P. A. McNaughton

Authors
  1. F. Fargon
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  2. P. A. McNaughton
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  3. F. V. Sepúlveda
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Fargon, F., McNaughton, P.A. & Sepúlveda, F.V. Possible involvement of GTP-binding proteins in the deactivation of an inwardly rectifying K+ current in enterocytes isolated from guinea-pig small intestine. Pflugers Arch. 417, 240–242 (1990). https://doi.org/10.1007/BF00370706

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  • DOI: https://doi.org/10.1007/BF00370706

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