Effect of salicylate on proteoglycan metabolism in normal canine articular cartilage in vitro

Abstract

In osteoarthritis, diminished aggregation of articular cartilage proteoglycans affects tissue biomechanics. Since salicylates are commonly employed in treatment of osteoarthritis, we examined the effect of sodium salicylate on proteoglycan metabolism and aggregation in normal canine articular cartilage. At salicylate concentrations of 10(-3)M, 5 X 10(-3)M and 10(-2)M, net proteoglycan synthesis in normal canine articular cartilage was 73%, 42% and 16% respectively, of control levels. Catabolism of glycosaminoglycans in the presence of 10(-3)M salicylate (which corresponds to a serum salicylate level of 20-25 mg %) was the same as that in control cartilage, while higher concentrations of the drug increased the rate of degradation. The hydrodynamic size of newly synthesized proteoglycan aggregates and of disaggregated proteoglycans was unaffected by sodium salicylate.