Blood-tissue exchange via transport and transformation by capillary endothelial cells.

• DOI: 10.1161/01.res.65.4.997
• Publication Date: 2012-06-12T00:17:09Z
• Authors: J B Bassingthwaighte; C Y Wang; I S Chan
• Keywords: Dilution

The escape of solutes from the blood during passage along capillaries in heart and skeletal muscle occurs via diffusion through clefts between endothelial cells and, for some solutes, adsorption to or transport across luminal plasmalemma cell. To quantitate rates permeation these two routes capillary wall, we have developed a linear model transendothelial illustrated its suitability design analysis multiple simultaneous indicator dilution curves an organ. Data should be obtained at least three solutes: 1) intravascular reference, albumin; 2) solute transported by cells; 3) another reference solute, same molecular size as 2, which neither binds nor traverses cell membranes. capillary-tissue convection-permeation is spatially distributed accounts axial variation concentrations, around cells, accumulation consumption within them, exchange with interstitium parenchymal heterogeneity regional flows. upslope highly sensitive unidirectional rate loss surface. There less sensitivity antiluminal surface, except when retention low. useful receptor kinetics using tracers steady-state conditions allows distinction equilibrium binding reaction limitations. Uptake surface are readily estimated fitting experimental curves. For adenosine fatty acids, 30-99% transcapillary extraction.