In vitro effect of select nonsteroidal antiinflammatory drugs on the synthesis and activity of anabolic regulatory factors produced by osteoarthritic and rheumatoid synovial tissue.

Nutriment replenished conditioned media derived from cultures of osteoarthritic and rheumatoid synovial tissue contain factors of variable molecular weight, independent of prostaglandin activity, which are capable of reversibly down-regulating cartilage matrix proteoglycan synthesis. Piroxicam significantly reduced anabolic suppressant factor production on an apparent selective basis. It could be shown to partially modify the chromatographic profile of newly synthesized osteoarthritic synovial tissue protein fractions containing suppressant activity. Dependent on experimental design, piroxicam also partially blocked inhibitory activity at a chondrocyte level. Indomethacin and sodium salicylate were essentially without effect.