Résumé
Vascular endothelial cell glycocalyx is a layer of glycoprotein complex located on the surface of endothelial cells, forming a selective permeation barrier on the surface of endothelial cells. In the present review, after a brief introduction of glycocalyx, the relationship between glycocalyx and mass transport under fluid sheer stress (FSS), especially the relationship between glycocalyx and macromolecules such as low density lipoprotein (LDL) has been discussed. This relationship was reflected as following: on the one hand, the thickness and integrity of the glycocalyx affects the concentration polarization of LDL and its transendothelial transport and heparan sulfate proteoglycan (HSPG) participates in the whole process of residual lipoproteins metabolism. On the other hand, ox-LDL, an oxidized product of LDL, destroys heparan sulfate (HS) which is a major component of the endothelial cell glycocalyx. The study on relationship between vascular endothelial glycocalyx and lipoproteins will provide a new clue to elucidate the pathogenesis of atherosclerosis and provide more evidence to view the glycocalyx as a new control target.
Résumé
Enrichment and immobilization of analytes by chemical bonding or physical adsorption is typically the first step in many commonly used analytical techniques. In this paper, we discuss a permeation drag based technique as an alternative approach for carrying out location-specific immobilization of macro-molecular analytes. Fluorescein isothiocyanate (FITC) labeled macromolecules and their complexes were enriched near the surface of ultrafiltration membranes and detected by direct visual observation and fluorescence imaging. The level of macromolecule enrichment at the immobilization sites could be controlled by manipulating the filtration rate and thereby the magnitude of permeation drag. Higher enrichment as indicated by higher fluorescence intensity was observed at higher filtration rates. Also, larger macromolecules were more easily enriched. The feasibility of using this technique for detecting immunocomplexes was demonstrated by carrying out experiments with FITC labeled bovine serum al-bumin (FITC-BSA) and its corresponding antibody. This permeation drag based enrichment technique could potentially be developed further to suit a range of analytical applications involving more sophis-ticated detection methods.