help button home button Biophys. J.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Subramanian, S.
Right arrow Articles by Wiesner, T. F.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Subramanian, S.
Right arrow Articles by Wiesner, T. F.

Biophys J, January 2001, p. 1-11, Vol. 80, No. 1

Underlying Mechanisms of Symmetric Calcium Wave Propagation in Rat Ventricular Myocytes

Saisunder Subramanian,* Sergej Viatchenko-Karpinski,dagger Valeriy Lukyanenko,dagger Sandor Györke,dagger and Theodore F. Wiesner*

 *Department of Chemical Engineering, Texas Tech University, Lubbock, Texas 79409, and  dagger Department of Physiology, Texas Tech University Health Science Center, Lubbock, Texas 79430 USA

Calcium waves in heart cells are mediated by diffusion-coupled calcium-induced calcium release. The waves propagate in circular fashion. This is counterintuitive in view of the accepted ultrastructure of the cardiac myocyte. The density of calcium release sites in the transverse direction is four times higher than in the longitudinal direction. Simulations with release sites localized along Z-lines and isotropic diffusion yielded highly elliptical, nonphysiological waves. We hypothesized that subcellular organelles counteracted the higher release site density along the Z-lines by acting as transverse diffusion barriers and sites of active calcium uptake. We quantified the reduction of transverse diffusion by microinjecting cells with the nonreactive dye fluorescein. The ratio of the radial diffusion coefficient to the longitudinal coefficient was 0.39. Inhibition of mitochondrial uptake by rotenone accelerated the wave in the transverse direction. Simulations with release sites clustered at the Z-lines and a transverse diffusion coefficient 50% of the longitudinal coefficient generated waves of ellipticity 2/1 (major axis along the Z-line). Introducing additional release sites between the Z-lines at a density 20% of that on the Z-lines produced circular waves. The experiments and simulations support the presence of transverse diffusion barriers, additional uptake sites, and possibly intermediate release sites as well.

Biophys J, January 2001, p. 1-11, Vol. 80, No. 1
© 2001 by the Biophysical Society   0006-3495/01/01/01/11  $2.00


This article has been cited by other articles:


Home page
 Biophys. JHome page
N. MacQuaide, J. Dempster, and G. L. Smith
Measurement and Modeling of Ca2+ Waves in Isolated Rabbit Ventricular Cardiomyocytes
Biophys. J., October 1, 2007; 93(7): 2581 - 2595.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
V. Lukyanenko, A. Ziman, A. Lukyanenko, V. Salnikov, and W. J. Lederer
Functional groups of ryanodine receptors in rat ventricular cells
J. Physiol., August 15, 2007; 583(1): 251 - 269.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
J.-i. Okada, S. Sugiura, S. Nishimura, and T. Hisada
Three-dimensional simulation of calcium waves and contraction in cardiomyocytes using the finite element method
Am J Physiol Cell Physiol, March 1, 2005; 288(3): C510 - C522.
[Abstract] [Full Text] [PDF]

Home page
 Biophys. JHome page
M. H. P. Wussling, I. Aurich, O. Knauf, H. Podhaisky, and H.-J. Holzhausen
Disposition of Calcium Release Units in Agarose Gel for an Optimal Propagation of Ca2+ Signals
Biophys. J., December 1, 2004; 87(6): 4333 - 4342.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2001 by the Biophysical Society.