| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Department of Bioengineering, University of Washington, Seattle, Washington 98195
Submitted 22 May 2003 ; accepted in final form 16 December 2003
Systems for describing myocardial cellular metabolism with appropriate thermodynamic constraints on reactions have to be on the basis of estimates of intracellular and mitochondrial concentrations of metabolites as driving forces for reactions. This requires that tissue composition itself must be modeled, but there is marked inconsistency in the literature and no full data set on hearts of any species. To formulate a self-consistent set of information on the densities, contents, or concentrations of chemical components and volumes of tissue spaces, we drew on information mostly on rats. From the data on densities, volumes, volume fractions, and mass fractions observed mainly on left ventricular myocardium, cytoplasm, and mitochondria and from morphometric data on cellular components and the vasculature, we constructed a matrix based on conservation laws for density, volume, and constituent composition. The four constituents were water, protein, fat, and solutes (or ash). To take into account the variances in the observed data sets, we used a constrained nonlinear least squares optimization to minimize the differences between the final results and the data sets. The results provide a detailed estimate of cardiac tissue composition, previously unavailable, for the translation of whole tissue concentrations or concentrations per gram protein into estimated local concentrations that are relevant to reaction processes. An example is that the concentrations of phosphocreatine and ATP in cytosolic water space are twice as high as their mean tissue concentrations. This conservation optimization method is applicable to any tissue or organ.
heart tissue; water content; cellular energetics; metabolic modeling
This article has been cited by other articles:
|
|
 |
|
  F. Wu, J. Zhang, and D. A. Beard Experimentally observed phenomena on cardiac energetics in heart failure emerge from simulations of cardiac metabolism PNAS, April 28, 2009; 106(17): 7143 - 7148. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. K. Dash and D. A. Beard Analysis of cardiac mitochondrial Na+-Ca2+ exchanger kinetics with a biophysical model of mitochondrial Ca2+ handing suggests a 3: 1 stoichiometry J. Physiol., July 1, 2008; 586(13): 3267 - 3285. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. H. Hankiewicz, P. H. Goldspink, P. M. Buttrick, and E. D. Lewandowski Principal strain changes precede ventricular wall thinning during transition to heart failure in a mouse model of dilated cardiomyopathy Am J Physiol Heart Circ Physiol, January 1, 2008; 294(1): H330 - H336. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Wang, J. Radhakrishnan, I. M. Ayoub, J. D. Kolarova, D. M. Taglieri, and R. J. Gazmuri Limiting sarcolemmal Na+ entry during resuscitation from ventricular fibrillation prevents excess mitochondrial Ca2+ accumulation and attenuates myocardial injury J Appl Physiol, July 1, 2007; 103(1): 55 - 65. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Wu, J. A. L. Jeneson, and D. A. Beard Oxidative ATP synthesis in skeletal muscle is controlled by substrate feedback Am J Physiol Cell Physiol, January 1, 2007; 292(1): C115 - C124. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. B Bassingthwaighte, G. M Raymond, J. D Ploger, L. M Schwartz, and T. R Bukowski GENTEX, a general multiscale model for in vivo tissue exchanges and intraorgan metabolism Phil Trans R Soc A, June 15, 2006; 364(1843): 1423 - 1442. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
