To demonstrate localization of hyaluronic acid (HA) in articular cartilage of the human femur, biotinylated HA-binding region, which specifically binds HA molecules, was applied to the tissue. In sections fixed by 2% paraformaldehyde-2% glutaraldehyde, HA staining was detected in lamina splendens and chondrocytes in the middle zone. By pretreatment with trypsin, intense HA staining appeared in the extracellular matrix of the deep zone and weak staining in the superficial and middle zones. Moreover, pre-treatment with chondroitinase ABC (CHase ABC) intensely enhanced the stainability for HA in the superficial and middle zones and weakly in the deeper zone. Combined pre-treatment of trypsin with CHase ABC abolished intra- and extracellular staining for HA in all zones. By microbiochemical study, the concentrations of HA and dermatan sulfate were high in the middle zone, whereas those of chondroitin sulfate and keratan sulfate were high in the deep zone. These results suggest that HA is abundantly synthesized in and secreted from the chondrocytes, particularly in the middle zone, whereas it is largely masked by proteoglycan constituents in the extracellular matrix.

The concentrations of hyaluronan (HA) and chondroitin sulfate (CS) in synovial fluids from patients with traumatic arthritis (TA) with and without hydrarthrosis were measured. The CS in synovial fluids was determined as a marker of cartilage destruction by high performance liquid chromotography. The concentration of HA in synovial fluids was lower in patients with hydrarthrosis than in healthy volunteers and patients with TA without hydrarthrosis, whereas the total amounts of HA and CS and the concentration of CS were higher in patients with hydrarthrosis. To investigate the relation between hydrarthrosis and production of HA in synovial tissues, TA synovial tissue biopsies were stained for HA with biotinylated HA binding region. The intensity of HA staining was higher in specimens from patients with hydrarthrosis than in normal and TA without hydrarthrosis specimens. Thus, there may be a correlation between hyperproduction of HA, cartilage destruction and increase in fluid volume in TA.

No abstract