J0202-1-4 Electrostatic Model for the Osmotic flow across the Endothelial Surface Glycocalyx

Abstract

Experimental studies have shown that a matrix layer of macromolecules covering the surface of microvessel walls, referred to as the endothelial surface glycocalyx layer (EGL), is negatively charged, and thus, the microvascular permeability to anionic macromolecules is lower than neutral or cationic ones. To investigate the electric charge effect on the material exchange across the microvessel wall, we develop an electrostatic model for the osmotic flow across the EGL when there is a difference in solute concentration. The EGL is modeled as a layer consisting of circular cylinders having a fixed surface charge that are aligned regularly. The expression of the osmotic reflection coefficient is derived for spherical solutes with a fixed surface charge suspended in an electrolyte. The repulsive interaction between the surface charges is found to increase the reflection coefficient. The results suggest that the charge density in the EGL could be about -30 mEq/l.