GLYCATED ALBUMIN STIMULATES FIBRONECTIN AND COLLAGEN-IV PRODUCTION BYGLOMERULAR ENDOTHELIAL-CELLS UNDER NORMOGLYCEMIC CONDITIONS

Albumin modified by Amadori glucose adducts, formed in increased amoun ts in diabetes, stimulates the synthesis of matrix by renal glomerular mesangial cells and has been causally linked to the pathogenesis of d iabetic nephropathy. However, the effect of glycated albumin on the bi ology of glomerular endothelial cells, which elaborate a basement memb rane that undergoes thickening in diabetes, has not been investigated. We used well-characterized rat glomerular endothelial cells to examin e the influence of glycated albumin on the synthesis of extracellular matrix proteins by these cells in culture. Concentrations of glycated albumin that are present in clinical specimens stimulate fibronectin a nd collagen TV production by glomerular endothelial cells, and this ef fect is operative under normoglycemic conditions. These results suppor t the hypothesis that increased glycated albumin contributes to glomer ular basement membrane thickening in diabetes. (C) 1997 Academic Press .