Home LiteratureArticle Details
PMID: 9450940 Published · ppublish English Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S.

Modulation of the frequency of spontaneous sarcoplasmic reticulum Ca2+ release events (Ca2+ sparks) by myoplasmic [Mg2+] in frog skeletal muscle.

The Journal of general physiology ·Vol. 111 ·No. 2 ·1998-02-00 ·Pages 207-24

Lacampagne A, Klein MG, Schneider MF

Abstract

The modulation by internal free [Mg2+] of spontaneous calcium release events (Ca2+ "sparks") from the sarcoplasmic reticulum (SR) was studied in depolarized notched frog skeletal muscle fibers using a laser scanning confocal microscope in line-scan mode (x vs. t). Over the range of [Mg2+] from 0.13 to 1.86 mM, decreasing the [Mg2+] induced an increase in the frequency of calcium release events in proportion to [Mg2+]-1.6. The change of event frequency was not due to changes in [Mg-ATP] or [ATP]. Analysis of individual SR calcium release event properties showed that the variation in event frequency induced by the change of [Mg2+] was not accompanied by any changes in the spatiotemporal spread (i.e., spatial half width or temporal half duration) of Ca2+ sparks. The increase in event frequency also had no effect on the distribution of event amplitudes. Finally, the rise time of calcium sparks was independent of the [Mg2+], indicating that the open time of the SR channel or channels underlying spontaneous calcium release events was not altered by [Mg2+] over the range tested. These results suggest that in resting skeletal fibers, [Mg2+] modulates the SR calcium release channel opening frequency by modifying the average closed time of the channel without altering the open time. A kinetic reaction scheme consistent with our results and those of bilayer and SR vesicle experiments indicates that physiological levels of resting Mg2+ may inhibit channel opening by occupying the site for calcium activation of the SR calcium release channel.

MeSH Terms
Adenine Nucleotides/pharmacology Animals Calcium/metabolism Electrophysiology Image Cytometry Image Processing, Computer-Assisted Kinetics Magnesium/metabolism Microscopy, Confocal Muscle Fibers, Skeletal/metabolism Muscle, Skeletal/metabolism,ultrastructure Rana pipiens Ryanodine Receptor Calcium Release Channel/metabolism Sarcoplasmic Reticulum/metabolism Spectrometry, Fluorescence
Chemicals
Adenine Nucleotides Ryanodine Receptor Calcium Release Channel Magnesium Calcium
Authors & Affiliations
3 authors, click to expand affiliations / ORCID
Lacampagne A
Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
Klein M G
Schneider M F
References (40)
40 references, click to expand
  1. 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
  2. Caffeine- and Ca2(+)-induced mechanical oscillations in isolated skeletal muscle fibres of the frog.
    J Muscle Res Cell Motil. 1989 Dec;10(6):437-45 PMID: 2613883
  3. Functional sensitivity of the native skeletal Ca(2+)-release channel to divalent cations and the Mg-ATP complex.
    Can J Physiol Pharmacol. 1992 Mar;70(3):394-402 PMID: 1318162
  4. Effects of low myoplasmic Mg2+ on calcium binding by parvalbumin and calcium uptake by the sarcoplasmic reticulum in frog skeletal muscle.
    J Gen Physiol. 1992 Jul;100(1):115-35 PMID: 1512554
  5. Low myoplasmic Mg2+ potentiates calcium release during depolarization of frog skeletal muscle fibers.
    J Gen Physiol. 1992 Jul;100(1):137-54 PMID: 1512555
  6. Valinomycin and excitation-contraction coupling in skeletal muscle fibres of the frog.
    J Physiol. 1992 Apr;449:219-35 PMID: 1326044
  7. Inactivation of the sarcoplasmic reticulum calcium channel by protein kinase.
    Nature. 1992 Oct 22;359(6397):739-41 PMID: 1331805
  8. Enhancement of Ca2+ release channel activity by phosphorylation of the skeletal muscle ryanodine receptor.
    FEBS Lett. 1993 Oct 18;332(3):237-42 PMID: 8405464
  9. Calcium sparks: elementary events underlying excitation-contraction coupling in heart muscle.
    Science. 1993 Oct 29;262(5134):740-4 PMID: 8235594
  10. Block by ruthenium red of the ryanodine-activated calcium release channel of skeletal muscle.
    J Gen Physiol. 1993 Dec;102(6):1031-56 PMID: 7510773
  11. Control of calcium release in functioning skeletal muscle fibers.
    Annu Rev Physiol. 1994;56:463-84 PMID: 8010748
  12. Ryanodine receptor/Ca2+ release channels and their regulation by endogenous effectors.
    Annu Rev Physiol. 1994;56:485-508 PMID: 7516645
  13. Effects of intracellular pH and [Mg2+] on excitation-contraction coupling in skeletal muscle fibres of the rat.
    J Physiol. 1994 Jul 15;478 ( Pt 2):331-9 PMID: 7965848
  14. Phosphorylation modulates the function of the calcium release channel of sarcoplasmic reticulum from skeletal muscle.
    Biophys J. 1994 Nov;67(5):1823-33 PMID: 7858121
  15. Imaging elementary events of calcium release in skeletal muscle cells.
    Science. 1995 Sep 22;269(5231):1723-6 PMID: 7569901
  16. Calcium inactivation of calcium release in frog cut muscle fibers that contain millimolar EGTA or Fura-2.
    J Gen Physiol. 1995 Aug;106(2):337-88 PMID: 8537819
  17. Two mechanisms of quantized calcium release in skeletal muscle.
    Nature. 1996 Feb 1;379(6564):455-8 PMID: 8559251
  18. 4-Chloro-m-cresol, a potent and specific activator of the skeletal muscle ryanodine receptor.
    Biochim Biophys Acta. 1996 Feb 9;1289(1):31-40 PMID: 8605229
  19. Response of ryanodine receptor channels to Ca2+ steps produced by rapid solution exchange.
    Biophys J. 1996 Aug;71(2):732-41 PMID: 8842211
  20. Sarcomeric calcium sparks activated by fiber depolarization and by cytosolic Ca2+ in skeletal muscle.
    Cell Calcium. 1996 Aug;20(2):123-8 PMID: 8889203
  21. Regulation of cardiac Ca2+ release channel (ryanodine receptor) by Ca2+, H+, Mg2+, and adenine nucleotides under normal and simulated ischemic conditions.
    Circ Res. 1996 Dec;79(6):1100-9 PMID: 8943948
  22. Factors shaping the confocal image of the calcium spark in cardiac muscle cells.
    Biophys J. 1996 Dec;71(6):2942-57 PMID: 8968567
  23. Repriming and activation alter the frequency of stereotyped discrete Ca2+ release events in frog skeletal muscle.
    J Physiol. 1996 Dec 15;497 ( Pt 3):581-8 PMID: 9003545
  24. Magnesium inhibition of ryanodine-receptor calcium channels: evidence for two independent mechanisms.
    J Membr Biol. 1997 Apr 1;156(3):213-29 PMID: 9096063
  25. Voltage dependence of the pattern and frequency of discrete Ca2+ release events after brief repriming in frog skeletal muscle.
    Proc Natl Acad Sci U S A. 1997 Sep 30;94(20):11061-6 PMID: 9380759
  26. Local control model of excitation-contraction coupling in skeletal muscle.
    J Gen Physiol. 1997 Oct;110(4):415-40 PMID: 9379173
  27. THE STABILITY CONSTANTS OF METAL-ADENINE NUCLEOTIDE COMPLEXES.
    Biochemistry. 1964 Jan;3:18-26 PMID: 14114498
  28. Numerical simulation of Ca2+ "sparks" in skeletal muscle.
    Biophys J. 1999 Nov;77(5):2333-57 PMID: 10545338
  29. Regenerative calcium release within muscle cells.
    Science. 1970 Jan 2;167(3914):58-9 PMID: 5409477
  30. Calcium induced release of calcium from the sarcoplasmic reticulum of skinned skeletal muscle fibres.
    Nature. 1970 Oct 3;228(5266):34-6 PMID: 5456208
  31. Adenine nucleotide stimulation of Ca2+-induced Ca2+ release in sarcoplasmic reticulum.
    J Biol Chem. 1984 Feb 25;259(4):2365-74 PMID: 6698971
  32. Sarcoplasmic reticulum contains adenine nucleotide-activated calcium channels.
    Nature. 1985 Aug 1-7;316(6027):446-9 PMID: 2410798
  33. Compartmentalization of the submembrane calcium activity during calcium influx and its significance in transmitter release.
    Biophys J. 1985 Sep;48(3):485-98 PMID: 2412607
  34. 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
  35. Ryanodine activation and inhibition of the Ca2+ release channel of sarcoplasmic reticulum.
    J Biol Chem. 1986 May 15;261(14):6300-6 PMID: 2422165
  36. Single channel measurements of the calcium release channel from skeletal muscle sarcoplasmic reticulum. Activation by Ca2+ and ATP and modulation by Mg2+.
    J Gen Physiol. 1986 Nov;88(5):573-88 PMID: 2431098
  37. Activation of the Ca2+ release channel of skeletal muscle sarcoplasmic reticulum by caffeine and related compounds.
    Arch Biochem Biophys. 1988 Nov 15;267(1):75-86 PMID: 2848455
  38. Structural evidence for direct interaction between the molecular components of the transverse tubule/sarcoplasmic reticulum junction in skeletal muscle.
    J Cell Biol. 1988 Dec;107(6 Pt 2):2587-600 PMID: 2849609
  39. Single cardiac sarcoplasmic reticulum Ca2+-release channel: activation by caffeine.
    Am J Physiol. 1989 Feb;256(2 Pt 2):H328-33 PMID: 2537030
  40. Voltage sensor of excitation-contraction coupling in skeletal muscle.
    Physiol Rev. 1991 Jul;71(3):849-908 PMID: 2057528
Article Info
Journal
The Journal of general physiology
Abbr.
J Gen Physiol
ISSN
0022-1295
DOI
10.1085/jgp.111.2.207
Published
1998-02-00
Pages
207-24
Language
English
Region
United States
NLM ID
2985110R
PMCID
PMC2222774
Subset
IM
Grants
NIAMS NIH HHS · R01-AR44197 · United States
NINDS NIH HHS · R01-NS23346 · United States
External Links
PubMed source DOI: 10.1085/jgp.111.2.207 PMC Full Text 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