“…EPARAr~ sulfate proteoglycans prove to play an important role in the regulation of the activities and bioavailabilities of a growing number of enzymes, enzyme inhibitors, adhesion molecules, and growth factors (Jackson et al, 1991). Heparan sulfate proteoglyeans that form part of the extracellular matrix function as binding sites for chymase (Sayama et al, 1987), antithrombin III (Pejler et al, 1987;de Agostini et al, 1990), protease nexin (Farrell et al, 1988), and FGFs (Gonzalez et al, 1990) which may provide the cells with matrix-bound reservoirs of these components. For basic FGF the interaction with the heparan sulfate of the matrix seems to metabolically stabilize the cytokine (Saksela et al, 1988), and to limit its diffusion and availability (Flaumenhaft et al, 1990), but active heparan sulfate growth factor complexes can be released from the matrix through limited proteolysis (Saksela and Rifkin, 1990) or partial degradation of the heparan sulfate residues (Ishal-Miehaeli et al, 1990).…”