Home LiteratureArticle Details
PMID: 1598189 Published · ppublish English Journal Article Research Support, Non-U.S. Gov't

Intracellular Mg2+ inhibits the IP3-activated IK(Ca) in NG108-15 cells. [Why intracellular citrate can be useful for recording IK(Ca)].

Pflugers Archiv : European journal of physiology ·Vol. 420 ·No. 3-4 ·1992-03-00 ·Pages 347-53

Robbins J, Cloues R, Brown DA

Abstract

Receptor-mediated formation of inositol 1,4,5-trisphosphate (IP3) can induce an outward Ca(2+)-activated K+ current [IK(Ca)] in some neural cells. We have investigated IK(Ca) activated by intracellular injections of IP3 in whole-cell patch-clamped neuroblastoma x glioma hybrid cells. The current could only be recorded reliably using citrate as the anion in the pipette, but not using acetate, aspartate, chloride, fluoride, gluconate or methylsulphate. This could be attributed to buffering of intracellular Mg2+ by citrate. Theoretical calculations suggested free [Mg2+] of 1.0 and 0.07 mM respectively in the acetate- and citrate-based recording solutions. Further, IP3-activated IK(Ca) could be recorded when the free Mg2+ level in the acetate, chloride or methylsulphate solutions was lowered to the range (0.05 mM) calculated for the citrate solution. Thus, raised [Mg2+] blocks IK(Ca). This appeared to be due to inhibition of the response to released Ca2+, since high [Mg2+] also blocked the response to intracellular injections of Ca2+ ions. Mean Mg2+ levels in intact neuroblastoma x glioma hybrid cells measured by Mag-Indo-1/AM fluorescence were estimated to be less than 0.14 mM. We therefore conclude that IP3-induced IK(Ca) is expressed under normal conditions, but may be subject to regulation by intracellular Mg2+.

MeSH Terms
Anions Bradykinin/pharmacology Calcium/metabolism Citrates/metabolism Inositol 1,4,5-Trisphosphate/physiology Magnesium/physiology Membrane Potentials Potassium/metabolism Tumor Cells, Cultured
Chemicals
Anions Citrates Inositol 1,4,5-Trisphosphate Magnesium Potassium Bradykinin Calcium
Authors & Affiliations
3 authors, click to expand affiliations / ORCID
Robbins J
Department of Pharmacology, University College London, UK.
Cloues R
Brown D A
References (42)
42 references, click to expand
  1. Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches.
    Pflugers Arch. 1981 Aug;391(2):85-100 PMID: 6270629
  2. Intracellular free magnesium in neurones of Helix aspersa measured with ion-selective micro-electrodes.
    J Physiol. 1984 Sep;354:303-17 PMID: 6481636
  3. Origin of calcium ions involved in the generation of a slow afterhyperpolarization in bullfrog sympathetic neurones.
    Pflugers Arch. 1983 Nov;399(3):194-202 PMID: 6419201
  4. Thyrotropin-releasing hormone stimulates a calcium-activated potassium current in a rat anterior pituitary cell line.
    J Physiol. 1987 Apr;385:611-25 PMID: 2443674
  5. Inositol 1,4,5-trisphosphate alters bursting pacemaker activity in Aplysia neurons: voltage-clamp analysis of effects on calcium currents.
    J Neurophysiol. 1988 Jul;60(1):86-104 PMID: 3136233
  6. Dual modulation of K channels by thyrotropin-releasing hormone in clonal pituitary cells.
    Proc Natl Acad Sci U S A. 1985 Jun;82(12):4282-6 PMID: 2408278
  7. Intracellular magnesium affects I(K) in single frog atrial cells.
    Am J Physiol. 1989 Nov;257(5 Pt 2):H1663-9 PMID: 2589519
  8. Inhibition of the M current in NG 108-15 neuroblastoma x glioma hybrid cells.
    Pflugers Arch. 1991 Jul;418(6):581-91 PMID: 1945751
  9. Calcium as a coagonist of inositol 1,4,5-trisphosphate-induced calcium release.
    Science. 1991 Apr 19;252(5004):443-6 PMID: 2017683
  10. Effects of intracellular free magnesium on calcium current in isolated cardiac myocytes.
    Science. 1988 Feb 12;239(4841 Pt 1):778-80 PMID: 2448878
  11. Ionic mechanism of the outward current induced by intracellular injection of inositol trisphosphate into Aplysia neurons.
    J Neurosci. 1987 May;7(5):1470-83 PMID: 2437264
  12. Effect of Mg2+ on the control of Ca2+ release in skeletal muscle fibres of the toad.
    J Physiol. 1991 Mar;434:507-28 PMID: 1708823
  13. Voltage-dependent magnesium block of adenosine-triphosphate-sensitive potassium channel in guinea-pig ventricular cells.
    J Physiol. 1987 Jun;387:251-72 PMID: 2443681
  14. Ca2+-dependent K+ channels in neuroblastoma hybrid cells activated by intracellular inositol trisphosphate and extracellular bradykinin.
    FEBS Lett. 1988 Oct 10;238(2):395-400 PMID: 3262538
  15. Direct measurement of intracellular free magnesium in frog skeletal muscle using magnesium-selective microelectrodes.
    Biochim Biophys Acta. 1984 May 22;804(1):1-7 PMID: 6609720
  16. Calcium-dependent current generating the afterhyperpolarization of hippocampal neurons.
    J Neurophysiol. 1986 Jun;55(6):1268-82 PMID: 2426421
  17. Electrophysiological responses to bradykinin and microinjected inositol polyphosphates in neuroblastoma cells. Possible role of inositol 1,3,4-trisphosphate in altering membrane potential.
    FEBS Lett. 1987 Apr 20;214(2):365-9 PMID: 3494634
  18. Two polyphosphatidylinositide metabolites control two K+ currents in a neuronal cell.
    Nature. 1986 Sep 25-Oct 1;323(6086):333-5 PMID: 2429190
  19. Inositol trisphosphate releases intracellularly stored calcium and modulates ion channels in molluscan neurons.
    J Neurosci. 1988 Jul;8(7):2544-55 PMID: 2470874
  20. Bradykinin-induced rapid breakdown of phosphatidylinositol 4,5-bisphosphate in neuroblastoma X glioma hybrid NG108-15 cells.
    J Biol Chem. 1984 Aug 25;259(16):10201-7 PMID: 6088487
  21. Intracellular calcium pools in neuroblastoma x glioma hybrid NG108-15 cells.
    J Neurochem. 1990 Oct;55(4):1281-6 PMID: 2144581
  22. Voltage- and calcium-activated potassium currents in mouse neuroblastoma x rat glioma hybrid cells.
    J Physiol. 1988 Mar;397:149-65 PMID: 2457695
  23. A new generation of Ca2+ indicators with greatly improved fluorescence properties.
    J Biol Chem. 1985 Mar 25;260(6):3440-50 PMID: 3838314
  24. Membrane current responses of NG108-15 mouse neuroblastoma x rat glioma hybrid cells to bradykinin.
    J Physiol. 1988 Mar;397:167-84 PMID: 2457696
  25. Rapid calcium release from cardiac sarcoplasmic reticulum vesicles is dependent on Ca2+ and is modulated by Mg2+, adenine nucleotide, and calmodulin.
    J Biol Chem. 1987 Mar 5;262(7):3065-73 PMID: 2434495
  26. Effects of inositol, 1,4,5-trisphosphate injections into cat spinal motoneurons.
    Can J Physiol Pharmacol. 1990 Aug;68(8):1062-8 PMID: 2390736
  27. A transient outward current in NG108-15 neuroblastoma x glioma hybrid cells.
    Pflugers Arch. 1990 Apr;416(1-2):130-7 PMID: 2352830
  28. Charybdotoxin, a protein inhibitor of single Ca2+-activated K+ channels from mammalian skeletal muscle.
    Nature. 1985 Jan 24-30;313(6000):316-8 PMID: 2578618
  29. Action potential repolarization and a fast after-hyperpolarization in rat hippocampal pyramidal cells.
    J Physiol. 1987 Apr;385:733-59 PMID: 2443676
  30. Kinetics of rapid Ca2+ release by sarcoplasmic reticulum. Effects of Ca2+, Mg2+, and adenine nucleotides.
    Biochemistry. 1986 Jan 14;25(1):236-44 PMID: 3754147
  31. Blockade of Ca-activated K conductance by apamin in rat sympathetic neurones.
    Br J Pharmacol. 1986 Jan;87(1):225-32 PMID: 3006852
  32. Muscarinic agonists and ATP increase the intracellular Ca2+ concentration in chick cochlear hair cells.
    J Physiol. 1990 Jan;420:127-48 PMID: 2324982
  33. Allosteric effects of Mg2+ on the gating of Ca2+-activated K+ channels from mammalian skeletal muscle.
    J Exp Biol. 1986 Sep;124:5-13 PMID: 2428908
  34. Inward rectification of a potassium channel in cardiac ventricular cells depends on internal magnesium ions.
    Proc Natl Acad Sci U S A. 1987 Apr;84(8):2560-4 PMID: 2436236
  35. Rectification of muscarinic K+ current by magnesium ion in guinea pig atrial cells.
    Am J Physiol. 1987 Jul;253(1 Pt 2):H210-4 PMID: 2440317
  36. Bradykinin-induced intracellular Ca2+ elevation in neuroblastoma X glioma hybrid NG108-15 cells; relationship to the action of inositol phospholipids metabolites.
    Brain Res. 1986 Jul 30;379(1):84-9 PMID: 3742218
  37. Calcium activates two types of potassium channels in rat hippocampal neurons in culture.
    J Neurosci. 1991 Jan;11(1):23-30 PMID: 1986065
  38. Bradykinin causes a transient rise of intracellular Ca2+-activity in cultured neural cells.
    Pflugers Arch. 1985 Oct;405(3):260-4 PMID: 4069982
  39. Inositol 1,4,5-trisphosphate and diacylglycerol mimic bradykinin effects on mouse neuroblastoma x rat glioma hybrid cells.
    J Physiol. 1988 Mar;397:185-207 PMID: 3261793
  40. Genotypic m3-Muscarinic Receptors Preferentially Inhibit M-currents in DNA-transfected NG108-15 Neuroblastoma x Glioma Hybrid Cells.
    Eur J Neurosci. 1991;3(8):820-824 PMID: 12106468
  41. Apamin as a selective blocker of the calcium-dependent potassium channel in neuroblastoma cells: voltage-clamp and biochemical characterization of the toxin receptor.
    Proc Natl Acad Sci U S A. 1982 Feb;79(4):1308-12 PMID: 6122211
  42. Gadolinium selectively blocks a component of calcium current in rodent neuroblastoma x glioma hybrid (NG108-15) cells.
    J Physiol. 1988 Apr;398:33-47 PMID: 3392676
Article Info
Journal
Pflugers Archiv : European journal of physiology
Abbr.
Pflugers Arch
ISSN
0031-6768
DOI
10.1007/BF00374469
Published
1992-03-00
Pages
347-53
Language
English
Region
Germany
NLM ID
0154720
Subset
IM
Grants
Wellcome Trust · United Kingdom
External Links
PubMed source DOI: 10.1007/BF00374469 View journal details
Analysis Services
Analysis Services

Contact

No. 2 Wenbo Road, Zhangqiu District, Jinan, Shandong

Qilu Normal University · Genelibs Bioinformatics Lab

750 Shunhua Rd, Jinan

2F, Bldg F, University Science Park

Tel: 0531-88819269

WeChat Official Account

Follow our WeChat subscription account for real-time updates and the latest in medical and biological research.


Business Email

E-mail: [email protected]

Copyright © 2026.Genelibs Jinan Honghui Biotechnology Co., Ltd. 鲁ICP备20007159号-2