Possible involvement of GTP-binding proteins in the deactivation of an inwardly rectifying K+current in enterocytes isolated from guinea-pig small intestine
✍ Scribed by F. Fargon; P. A. McNaughton; F. V. Sepúlveda
- Publisher
- Springer
- Year
- 1990
- Tongue
- English
- Weight
- 310 KB
- Volume
- 417
- Category
- Article
- ISSN
- 0031-6768
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✦ Synopsis
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 inwardlyrectifying 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 rain, suggesting a multistep mechanism. CI" 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.