EFFECTS OF HYALURONIC-ACID ON THE RELEASE OF CARTILAGE MATRIX PROTEOGLYCAN AND FIBRONECTIN FROM THE CELL-MATRIX LAYER OF CHONDROCYTE CULTURES - INTERACTIONS BETWEEN HYALURONIC-ACID AND CHONDROITIN SULFATE GLYCOSAMINOGLYCAN

Hyaluronic acid (HA) of large sizes suppressed the release of cartilag e matrix proteoglycan, fibronectin, and other macromolecules from the cell matrix layer of chondrocyte cultures, perhaps because HA of large sizes formed a viscous barrier in the matrix by its interactions with other extracellular matrix macromolecules. To test this possibility, we determined the viscosity of solutions containing HA of various size s in the presence of proteoglycan monomer or chondroitin sulfate glyco saminoglycan (GAG). Not only the monomer but also chondroitin sulfate increased the viscosity of HA solutions, depending on the size of HA. These findings suggest that HA of large sizes increases the viscosity near the surface of articular cartilage by sugar-sugar and by sugar-pr otein interactions, and that the increase of viscosity is involved in the protective action of HA on arthritic cartilage.