Calcium Sparks in Skeletal Muscle Fibers
Catherine
Lloyd
Bioengineering Institute, University of Auckland
Model Status
This model is coded according to the description in the publication but is not able to reproduce the published results.
ValidateCellML detects units inconsistencies within this model.
Model Structure
The activation of Ca2+ sparks is an essential step in cardiac excitation-contraction coupling. A Ca2+ spark arises when sarcoplasmic reticulum (SR) Ca2+-release channels (ryanodine receptors, or RyRs) open, allowing Ca2+ to diffuse out of the intracellular store, down its electrochemical gradient into the cytoplasm. The increase in intracellular calcium concentration ([Ca2+]i) is recognised as a Ca2+ spark. After release, Ca2+ diffuses through the cytoplasm and binds to buffers such as troponin, ATP, parvalbumin and the SR Ca2+ pump.
In their 2002 paper, S.M. Baylor, S. Hollingworth and W.K. Chandler model Ca2+ sparks in frog intact skeletal muscle fibers. The model calculates changes in the concentration of free Ca2+ and of Ca2+ bound to the buffers and to the Ca2+ indicator fluo-3 (see below).
The complete original paper reference is cited below:
Comparison of Simulated and Measured Calcium Sparks in Intact Skeletal Muscle Fibers of the Frog, S.M. Baylor, S. Hollingworth and W.K. Chandler, 2002,
Journal of General Physiology
, 120, 349-368. (Full text and PDF versions of the article are available to subscribers on the Journal of General Physiology website.) PubMed ID: 12198091
The raw CellML descriptions of the model can be downloaded in various formats as described in .
reaction_diagram
Schematic diagrams of the Ca2+ binding reactions for various buffers and indicators: A The reaction of Ca2+ with ATP in the presence of free Mg2+, B Reaction of Ca2+ with protein (Pr) and fluo-3 (Fluo), C Competitive reaction of Ca2+ and Mg2+ with parvalbumin (Parv), D Binding reaction of Ca2+ binding and transport by the sarcoplasmic reticulum Ca2+ pump (E), E One-step reaction of Ca2+ with Troponin (Trop), and F Two-step reaction of Ca2+ with Troponin (Trop).
skeletal muscle
calcium dynamics
The University of Auckland, Bioengineering Institute
Catherine Lloyd
S
Baylor
M
Baylor, Hollingworth and Chandler's 2002 model of the Ca2+-ATP binding
reaction in skeletal myocytes.
Skeletal Myocyte
Frog
2009-05-05T12:08:14+12:00
Comparison of Simulated and Measured Calcium Sparks in Intact Skeletal Muscle Fibers of the Frog
120
349
368
12198091
This is the CellML description of Baylor, Hollingworth and Chandler's
2002 model of the Ca2+-ATP binding reaction in skeletal myocytes.
James
Lawson
Richard
c.lloyd@auckland.ac.nz
W
Chandler
K
The University of Auckland
The Bioengineering Institute
The new version of this model has been re-coded to remove the reaction element and replace it with a simple MathML description of the model reaction kinetics. This is thought to be truer to the original publication, and information regarding the enzyme kinetics etc will later be added to the metadata through use of an ontology.
The model runs in the PCEnv simulator but gives a flat/almost flat output.
updated curation status
S
Hollingworth
2007-05-23T00:00:00+00:00
Journal of General Physiology
2007-06-05T09:15:51+12:00
Catherine
Lloyd
May
keyword
Catherine
Lloyd
May
2002-09-01