Journal ArticleDOI
Intracellular ATP directly blocks K + channels in pancreatic B-cells
TLDR
During patch–clamp studies of proton inhibition of Ca2+-activated K+ channels in B-cells, a second K+-selective channel is identified which is rapidly and reversibly inhibited by ATP applied to the cytoplasmic surface of the membrane.Abstract:
It is known that glucose-induced depolarization of pancreatic B-cells is due to reduced membrane K+-permeability and is coupled to an increase in the rate of glycolysis, but there has been no direct evidence linking specific metabolic processes or products to the closing of membrane K+ channels During patch-clamp studies of proton inhibition of Ca2+-activated K+ channels [GK(Ca)] in B-cells, we identified a second K+-selective channel which is rapidly and reversibly inhibited by ATP applied to the cytoplasmic surface of the membrane This channel is spontaneously active in excised patches and frequently coexists with GK(Ca) channels yet is insensitive to membrane potential and to intracellular free Ca2+ and pH Blocking of the channel is ATP-specific and appears not to require metabolism of the ATP This ATP-sensitive K+ channel [GK(ATP)] may be a link between metabolism and membrane K+-permeability in pancreatic B-cellsread more
Citations
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Journal ArticleDOI
Reconstitution of IKATP: an inward rectifier subunit plus the sulfonylurea receptor.
Nobuya Inagaki,Tohru Gonoi,John P. Clement,Noriyuki Namba,Johji Inazawa,Gabriela Gonzalez,Lydia Aguilar-Bryan,Susumu Seino,Joseph Bryan +8 more
TL;DR: Gene mapping data indicate that these pancreatic β cell potassium channels are a complex composed of at least two subunits-BIR, a member of the inward rectifier potassium channel family, and SUR, a members of the ATP-binding cassette superfamily.
Journal ArticleDOI
Diversity and ubiquity of K channels.
TL;DR: In hippocampal neurons, a Ca-activated K channel which may be responsible for the slow AHP has been identified in single channel recordings, however, this channel has unique properties and it is not blocked by Apamin, suggesting that more than one subclass of Ca- activated K channel may mediate slow AHPs.
Journal ArticleDOI
Inwardly Rectifying Potassium Channels: Their Structure, Function, and Physiological Roles
Hiroshi Hibino,Atsushi Inanobe,Kazuharu Furutani,Shingo Murakami,Ian Findlay,Yoshihisa Kurachi +5 more
TL;DR: The crystal structure of different Kir channels is opening the way to understanding the structure-function relationships of this simple but diverse ion channel family.
Journal ArticleDOI
Triggering and amplifying pathways of regulation of insulin secretion by glucose.
TL;DR: Besides the available drugs that act on K(ATP) channels and increase the triggering signal, novel drugs that correct a deficient amplifying pathway would be useful to restore adequate insulin secretion in type 2 diabetic patients.
Journal ArticleDOI
Electrophysiology of the pancreatic beta-cell.
References
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Journal ArticleDOI
Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches.
TL;DR: The extracellular patch clamp method, which first allowed the detection of single channel currents in biological membranes, has been further refined to enable higher current resolution, direct membrane patch potential control, and physical isolation of membrane patches.
BookDOI
Single-channel recording
Bert Sakmann,Erwin Neher +1 more
TL;DR: A Practical Guide to Patch Clamping R.H. Penner, C.W. Heinemann, and P. Jonas.
Journal ArticleDOI
ATP-regulated K + channels in cardiac muscle
TL;DR: Application of the patch-clamp technique to CN-treated mammalian heart cells reveals specific K+ channels which are depressed by intracellular ATP (ATPi) at levels greater than 1 mM, which seems to be important for regulation of cellular energy metabolism in the control of membrane excitability.
Journal ArticleDOI
The stimulus-secretion coupling of glucose-induced insulin release. XXXV. The links between metabolic and cationic events.
Willy Malaisse,Willy Malaisse,J C Hutton,Shoji Kawazu,André Herchuelz,Isabel Valverde,Abdullah Sener +6 more
TL;DR: It is proposed that the generation of both NAD(P)H and H+ participates in the coupling of glucose metabolism to distal events in the secretory sequence, especially the ionophoretic process of Ca2+ inward and outward transport, and that changes in these parameters occur in concert with an increased turn-over rate of high-energy phosphate intermediates.
Journal ArticleDOI
Single Ca2+-activated nonselective cation channels in neuroblastoma.
TL;DR: This work has studied the response of membrane patches from neuroblastoma cells to intracellular Ca2+ ions, and found a class of nonselective cation channels activated by micromolar concentrations of Ca2+, which suggests that this hitherto scarcely recognized channel species may be more widely distributed than previously supposed.