Effects of certain antiarthritic agents on the synthesis of type II collagen and glycosaminoglycans in rat chondrosarcoma cultures.

Cartilage destruction is a characteristic feature of osteoarthritis. Treatment with certain nonsteroidal anti-inflammatory drugs could exacerbate cartilage destruction by impairing the synthesis of cartilage matrix proteins, type II collagen and proteoglycan. In order to monitor the changes occurring in cartilage collagen synthesis, we developed a type II collagen specific ELISA. The effects of antiarthritic agents on type II collagen and glycosaminoglycan synthesis were examined in rat chondrosarcoma cultures. Drugs were added to the monolayer cultures and 4 days later the total type II collagen, as determined by the type II collagen ELISA, and glycosaminoglycan content, as measured by dimethyl-methylene blue dye binding assay, was measured. All drugs except tiaprofenic acid decreased type II collagen synthesis by at least 40% at 100 micrograms/ml. Tiaprofenic acid at 1 microgram/ml increased type II collagen content by 54% of the controls. Glycosaminoglycan synthesis was decreased by acetylsalicylic acid, diclofenac and tiaprofenac acid, at 50 micrograms/ml or above. Indomethacin, naproxen and dexamethasone had no effect. Interestingly, tenidap stimulated the glycosaminoglycan synthesis by 32% at 100 micrograms/ml. We show that the combination of chondrosarcoma cultures, type II collagen specific ELISA and dimethylmethylene blue dye binding assay serves as a useful model for screening the effects of agents capable of modulating type II collagen and glycosaminoglycan synthesis.