Blood tissue exchange model for heart capillaries uses literature values for constants to fit multiple indicator dilution data from tracer data through perfused dog hearts. Estimates for permeability surface areas for each solute are made.

Description

This model expands on the framework of the BTEX40 model, using the physiologically correct variables for blood tissue exchange through capillaries in the heart. In order to determine permeability-surface areas and extraction values for flows through the organ, multiple indicator dilution data is used from canine hearts. This code also allows comparison of the fitted PSg values to those offered by the traditional Crone equation. The method uses indicator solutes such as labeled albumin, sucrose, glucose, potassium and sodium to demonstrate the uptake and outflow of each solute. The extractions of the latter solutes are determined with respect to albumin, with only vascular behaviors, and these extractions can be used to compare to the calculations of permeability surface area values for across the endothelial cell gap for each of the solutes.

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.