A quantitative model for refilling of the sarcoplasmic reticulum during vascular smooth muscle asynchronous [Ca2+] oscillations
Abstract
We have developed a quantitative model for the creation of cytoplasmic Ca2+ gradients near the inner surface of the plasma membrane (PM). In particular we simulated the refilling of the sarcoplasmic reticulum (SR) via PM-SR junctions during asynchronous [Ca2+] oscillations in smooth muscle cells of the rabbit inferior vena cava. We have combined confocal microscopy data on the [Ca2+] oscillations, force transduction data from cell contraction studies and electron microscopic images to build a basis for computational simulations that model the transport of calcium ions from Na+/Ca2+ exchangers (NCX) on the PM to sarcoplasmic/endoplasmic reticulum Ca2+ ATPase (SERCA) pumps on the SR as a three-dimensional random walk through the PM-SR junctional cytoplasmic spaces. Electron microscopic ultrastructural images of the smooth muscle cells were elaborated with software algorithms to produce a very clear and dimensionally accurate picture of the PM-SR junctions. From this study, we conclude that it is plausible and possible for enough Ca2+ to pass through the PM-SR junctions to replete the SR during the regenerative Ca2+ release, which underlies agonist induced asynchronous Ca2+ oscillations in vascular smooth muscle.
Keywords
Cite
@article{arxiv.q-bio/0603001,
title = {A quantitative model for refilling of the sarcoplasmic reticulum during vascular smooth muscle asynchronous [Ca2+] oscillations},
author = {Nicola Fameli and Cornelis Van Breemen and Kuo-Hsing Kuo},
journal= {arXiv preprint arXiv:q-bio/0603001},
year = {2009}
}
Comments
21 pages, 8 figures, submitted to "Cell Calcium"; In 2nd version, expanded sections 3.3, 3.4, 4, added Fig.9, provided separate result files (1 animation and 3 3D graphs; article now 28 pages and 9 figures), accepted for publication in Cell Calcium on 7 February 2007. Animation is in the data directory and be obtained by downloading source package