Cytosolic ADP enhances the sensitivity to tolbutamide of ATP‐dependent K+ channels from pancreatic B‐cells
Authors:
- S. LinsSLS. Lins
- T. Ohno-ShosakuTOT. Ohno-Shosaku
- G. TrubeGTG. Trube
- U. PantenUPU. Panten
- 7 November 1988
- journal article
- Published by Wiley in FEBS Letters
- Vol. 239 (2) , 241-244
Abstract
The effects of intracellular purine nucleotides on tolbutamide‐induced block of ATP‐dependent K+ channels from mouse pancreatic B‐cells were studied using the patch‐clamp technique. When applied to the inside of excised patches tolbutamide alone blocked channel activity half‐maximally at 55μM and the concentration‐response curve for the inhibition of K+ channels by tolbutamide was flat. ADP (1 mM), but not other nucleotides (AMP, GTP or GDP) increased the steepness of the concentration‐response curve and decreased the half‐maximally effective tolbutamide concentration to 4.2 μM. It is suggested that the ATP‐dependent K+ channel or a closely related structure contains a receptor which is accessible for cytosolic ADP and controls the sensitivity to tolbutamide.Keywords
This publication has 14 references indexed in Scilit:
- Concentration-dependent effects of tolbutamide, meglitinide, glipizide, glibenclamide and diazoxide on ATP-regulated K+ currents in pancreatic B-cellsNaunyn-Schmiedeberg's Archives of Pharmacology, 1988
- Interaction of diazoxide, tolbutamide and ATP4− on nucleotide-dependent K+ channels in an insulin-secreting cell lineThe Journal of Membrane Biology, 1987
- Dual effects of ATP on K+ currents of mouse pancreatic ?-cellsPflügers Archiv - European Journal of Physiology, 1987
- The ATP‐sensitivity of K+ channels in rat pancreatic B‐cells is modulated by ADPFEBS Letters, 1986
- Intracellular ADP activates K+ channels that are inhibited by ATP in an insulin‐secreting cell lineFEBS Letters, 1986
- Opposite effects of tolbutamide and diazoxide on the ATP-dependent K+ channel in mouse pancreatic ?-cellsPflügers Archiv - European Journal of Physiology, 1986
- A metabolite-regulated potassium channel in rat pancreatic B cells.Proceedings of the National Academy of Sciences, 1986
- Glucose dependent K+-channels in pancreatic?-cells are regulated by intracellular ATPPflügers Archiv - European Journal of Physiology, 1985
- THE SULPHONYLUREA RECEPTOR MAY BE AN ATP-SENSITIVE POTASSIUM CHANNELThe Lancet, 1985
- Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patchesPflügers Archiv - European Journal of Physiology, 1981