Two region multi-path BTEX model. Used to model D-glucose uptake in the heart. Model fit to Kuikka et al. 1986 rabbit heart data.

Description

   Multiple indicator dilution (MID) analysis for the estimation of capillary permeability in the heart.
 The MID principle is to analyze the cellular permeability surface area product for the target solute, 
 D-glucose, against two reference solutes, one to characterize the intravascular transport function, 
 href(t) through the intact organ (131I-albumin in this case), an extracellular one of the same 
 molecular weight as the target solute in order to characterize the combination of permeation through 
 the inter-endothelial cleft (using L-glucose), and the target solute, D-glucose that is taken up by 
 cells and metabolized.
   This model is an axially distributed two region blood tissue exchange model, a reduced form of the 
 expected plasma-ISF-cell three region model used to describe the myocardial uptake and metabolism of 
 D-glucose. The model is fitted to the data from Kuikka (1986), which describes the experiments using 
 indicator dilution techniques in isolated perfused rabbit hearts. Instead of the parenchymal cell 
 premeability-surface area product (PS) and subsequent intracellular reaction the disappearance of 
 D-glucose from the interstitial space region is modeled as a unidirectional first order consumption 
 (G_D-glucisf) rather than the premeability and consumption in a third region (myocardial cells).
   The model also takes into account capillary flow heterogeneity through the heart using 10 pathways 
 in parallel with relative flows weight to represent the pdf of regional flows measured experimentally 
 using microsphere deposition densities in the tissue. 

There are two related models to this one: Kuikka 1986 three region BTEX, a three region model where a permeability and consumption term for a third region (myocardial cells) replaces the consumption term in the second region (interstitial fluid). This gives a better fit at later times of the outflow curves. This three region model fits all the data sets necessary to reproduce the figures in the Kuikka et al 1986 paper. The second one, Kuikka 1986 experiment, is the same three region model as above but includes parameter fits to all data summarized in Tables 1 and 2 of Kuikka 1986 paper.

Kuikka MID Data

The MID glucose datasets published in the Kuikka et al. 1986 paper are available on the Physionet web site. At the Physionet web site search for 'Cardiac Physiome Kuikka glucose' in the PhysioNetWorks area (you will need a free, personal account to access it).

Equations

The equations for this model may be viewed by running the JSim model applet and clicking on the Source tab at the bottom left of JSim's Run Time graphical user interface. The equations are written in JSim's Mathematical Modeling Language (MML). See the Introduction to MML and the MML Reference Manual. Additional documentation for MML can be found by using the search option at the Physiome home page.