A. Glucosamine treatment increases 35SO4 incorporation into PG. Endothelial cells were labeled with 35S sulfate (25 μCi/ml) in medium alone (Control) or medium containing 30 mM glucose or 2.5 mM glucosamine 16 h. Radioactivity associated with proteoglycans (PG) from cells, media and extracellular matrix was determined. Values are expressed as mean ± SD B. Glucosamine mediated increase in PG is mostly in heparan sulfate proteoglycans (HSPG). Media and matrix PG prepared from control and glucosamine treated endothelial cells were treated with chondroitinase ABC for 4 h at 37°C and undigested PG were precipitated and determined as HSPG. To determine if the undigested glycosaminoglycan (GAG) is HS, aliquots were subjected to low pH nitrous acid digestion. 1C. Glucose and glucosamine effects on perlecan mRNA (Real time PCR – 1C bar) and protein (immunoprecipitated protein in media 1C line) p < 0.01.