AJP - Heart and Circulatory Physiology, Vol 259, Issue 1 162-H166, Copyright © 1990 by American Physiological Society
Permeability of neutral vs. anionic dextrans in cultured brain microvascular endothelium
G. Sahagun, S. A. Moore and M. N. Hart
Department of Pathology, University of Iowa, Iowa City 52242.
The luminal surface of vascular endothelium contains glycocalyx residues
that establish an overall negative charge. Recent evidence has suggested
that local endothelial surface charge properties may account for the
permeability properties of various macromolecules. It has also been
suggested that altered membrane charge on the luminal side may play a role
in thrombogenesis and atherogenesis. The relationship of macromolecule
charge to endothelial cell permeability was examined in vitro using mouse
brain microvessel endothelial cells grown to confluence on a nitrocellulose
filter separating a double-chamber system. Endothelial permeability to 4K
and 10K fluorescein-labeled neutral dextrans was compared with the
permeability to 4K and 10K fluorescein-labeled anionic dextrans (sulfated).
After 1 h, there was significantly greater permeability of neutral
fluorescein-labeled dextran than of anionic fluorescein-labeled dextran in
each particle size. In addition, there was significantly greater
permeability of 4K than 10K fluorescein-labeled dextrans of either charge.
The findings indicate that charge in addition to size plays an important
role in the movement of macromolecules across cultured microvascular
endothelial cells.
