The in vitro effect of six NSAIDs on the glycosaminoglycan metabolism of rabbit chondrocytes.

The effects of NSAIDs on glycosaminoglycan (GAG) metabolism in vitro were studied in isolated chondrocytes from the weight-bearing cartilage of the hindleg knees of five mature rabbits separately. After confluence, secondary cultures were incubated for three days with six different NSAIDs at various concentrations: diclofenac sodium and indomethacin (0.4-50 micrograms/ml), piroxicam, naproxen and ibuprofen (4-100 micrograms/ml) and salicylic acid (8-1000 micrograms/ml). All NSAIDs significantly inhibited total 35S uptake in GAGs both in matrix and in medium in high concentrations. At low concentrations none of the NSAIDs significantly influenced the chondrocyte metabolism of GAG. The NSAID influence on keratan sulphate metabolism was variable.