Kupferman, R., Mitra, P. P., Hohenberg, P. C., Wang, S. S. H. (1997) Analytical calculation of intracellular calcium wave characteristics. Biophysical Journal, 72 (6). pp. 2430-2444. ISSN 00063495 (ISSN)
Abstract
We present a theoretical analysis of intracellular calcium waves propagated by calcium feedback at the inositol 1,4,5-trisphosphate (IP3) receptor. The model includes essential features of calcium excitability, but is still analytically tractable. Formulas are derived for the wave speed, amplitude, and width. The calculations take into account cytoplasmic Ca buffering, the punctate nature of the Ca release channels, channel inactivation, and Ca pumping. For relatively fast buffers, the wave speed is well approximated by V(α) = (J(eff)D(eff)/C0)(1/2), where J(eff) is an effective, buffered source strength; D(eff) is the effective, buffered diffusion constant of Ca; and C0 is the Ca threshold for channel activation. It is found that the saturability and finite on-rate of buffers must be taken into account to accurately derive the wave speed and front width. The time scale governing Ca wave propagation is T(r), the time for Ca release to reach threshold to activate further release. Because IP3 receptor inactivation is slow on this time scale, channel inactivation does not affect the wave speed. However, inactivation competes with Ca removal to limit wave height and front length, and for biological parameter ranges, it is inactivation that determines these parameters. Channel discreteness introduces only small corrections to wave speed relative to a model in which Ca is released uniformly from the surface of the stores. These calculations successfully predict experimental results from basic channel and cell parameters and explain the slowing of waves by exogenous buffers.
| Item Type: | Paper |
|---|---|
| Uncontrolled Keywords: | adenosine triphosphatase calcium buffer calcium calcium channel inositol 1,4,5 trisphosphate receptor ryanodine receptor analytic method article calcium cell level calcium transport calculation diffusion coefficient feedback system oscillation velocity Animals Biophysics Buffers Calcium Channels Inositol 1,4,5-Trisphosphate Intracellular Fluid Ion Transport Mice Models Biological Receptors Cytoplasmic and Nuclear Tumor Cells Cultured |
| Subjects: | bioinformatics > computational biology organs, tissues, organelles, cell types and functions > tissues types and functions > ion transport organs, tissues, organelles, cell types and functions > tissues types and functions > transport > ion transport |
| CSHL Authors: | |
| Communities: | CSHL labs > Mitra lab |
| Depositing User: | CSHL Librarian |
| Date: | 1997 |
| Date Deposited: | 04 Apr 2012 19:57 |
| Last Modified: | 10 Feb 2017 17:09 |
| PMCID: | PMC1184442 |
| Related URLs: | |
| URI: | https://repository.cshl.edu/id/eprint/25843 |
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