Block of ATP-sensitive K+ channels in isolated mouse pancreatic beta-cells by 2,3-butanedione monoxime. 1994

P A Smith, and B A Williams, and F M Ashcroft
University Laboratory of Physiology, Oxford.

1. The patch-clamp technique has been used to examine the action of the chemical phosphatase 2,3-butanedione monoxime (BDM) on ATP-sensitive K+ channels (KATP-channels) from mouse isolated pancreatic beta-cells in the absence of ATP and Mg2+. 2. BDM reversibly inhibited whole-cell KATP-currents with a concentration for half maximal inhibition (K(i)) of 15 +/- 1 mM and a Hill coefficient (n) of 2.5 +/- 0.2 (n = 4). 3. In outside-out patches, external BDM reversibly reduced the activity of single KATP-channels with an affinity similar to that observed in whole-cell recordings (K(i) = 11 +/- 3 mM, n = 2.0 +/- 0.3, n = 7). In inside-out patches, internally applied BDM also reversibly blocked the activity of KATP-channels (K(i) = 31 +/- 2 mM, n = 2.2 +/- 0.4, n = 8). In both excised patch configurations, BDM decreased the mean open life-time and the burst duration, thereby producing a decrease in the channel open probability. The drug had no effect on the short intraburst closed times. 4. BDM had no effect on the single-channel current amplitude. 5. The results suggest that BDM blocks the KATP-channel directly, by mechanisms independent of channel dephosphorylation.

UI MeSH Term Description Entries
D007515 Islets of Langerhans Irregular microscopic structures consisting of cords of endocrine cells that are scattered throughout the PANCREAS among the exocrine acini. Each islet is surrounded by connective tissue fibers and penetrated by a network of capillaries. There are four major cell types. The most abundant beta cells (50-80%) secrete INSULIN. Alpha cells (5-20%) secrete GLUCAGON. PP cells (10-35%) secrete PANCREATIC POLYPEPTIDE. Delta cells (~5%) secrete SOMATOSTATIN. Islands of Langerhans,Islet Cells,Nesidioblasts,Pancreas, Endocrine,Pancreatic Islets,Cell, Islet,Cells, Islet,Endocrine Pancreas,Islet Cell,Islet, Pancreatic,Islets, Pancreatic,Langerhans Islands,Langerhans Islets,Nesidioblast,Pancreatic Islet
D007700 Kinetics The rate dynamics in chemical or physical systems.
D008564 Membrane Potentials The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization). Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D002478 Cells, Cultured Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others. Cultured Cells,Cell, Cultured,Cultured Cell
D002801 Cholinesterase Reactivators Drugs used to reverse the inactivation of cholinesterase caused by organophosphates or sulfonates. They are an important component of therapy in agricultural, industrial, and military poisonings by organophosphates and sulfonates. Insecticides, Organophosphate, Antagonists,Insecticides, Organothiophosphate, Antagonists,Organophosphate Insecticide Antagonists,Organothiophosphate Insecticide Antagonists,Antagonists, Organophosphate Insecticide,Antagonists, Organothiophosphate Insecticide,Insecticide Antagonists, Organophosphate,Insecticide Antagonists, Organothiophosphate,Reactivators, Cholinesterase
D003931 Diacetyl Carrier of aroma of butter, vinegar, coffee, and other foods. 2,3-Butanedione,Biacetyl,Diketobutane,Dimethyldiketone,Dimethylglyoxal,2,3 Butanedione
D004594 Electrophysiology The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
D000255 Adenosine Triphosphate An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter. ATP,Adenosine Triphosphate, Calcium Salt,Adenosine Triphosphate, Chromium Salt,Adenosine Triphosphate, Magnesium Salt,Adenosine Triphosphate, Manganese Salt,Adenylpyrophosphate,CaATP,CrATP,Manganese Adenosine Triphosphate,MgATP,MnATP,ATP-MgCl2,Adenosine Triphosphate, Chromium Ammonium Salt,Adenosine Triphosphate, Magnesium Chloride,Atriphos,Chromium Adenosine Triphosphate,Cr(H2O)4 ATP,Magnesium Adenosine Triphosphate,Striadyne,ATP MgCl2
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D015221 Potassium Channels Cell membrane glycoproteins that are selectively permeable to potassium ions. At least eight major groups of K channels exist and they are made up of dozens of different subunits. Ion Channels, Potassium,Ion Channel, Potassium,Potassium Channel,Potassium Ion Channels,Channel, Potassium,Channel, Potassium Ion,Channels, Potassium,Channels, Potassium Ion,Potassium Ion Channel

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