Receptors specific for Amadori-modified glycated albumin on murine endothelial cells.

Albumin modified by Amadori glucose adducts has been shown to modulate endothelial and glomerular mesangial cell biology. Recognizing that circulating proteins may trigger cellular events through ligand binding, we examined murine aortic endothelial cells for the expression of a receptor system that recognizes fructosyllysine epitopes in glycated albumin. Endothelial cells contain membrane-associated polypeptides that bind Amadori-modified glycated albumin and exhibit traditional receptor characteristics of dose-responsivity, saturability and ligand specificity. Nonglycated albumin does not compete for binding to the receptor, and the interaction of glycated albumin with its receptor is blocked by a monoclonal antibody that selectively reacts with the Amadori adduct in glycated albumin. The findings suggest that a ligand-receptor system specific to Amadori glucose adducts mediates the biologic effects of glycated albumin.