In conclusion, the data obtained from the present study show that TA has less effect than indomethacin or ASA on cultured chondrocytes in gene expression and synthesis of collagen. These findings cannot be directly interpolated to clinical application, but attention to pharmacologic activities of NSAIDs on chondrocytes may have future applications. Two major NSAIDs, TA, indomethacin, and ASA, were examined for their effects on the biosynthesis and gene expression of articular cartilage collagen. The biosynthesis of type II collagen was suppressed to 70% to 80% of the control by indomethacin and ASA. TA did not suppress collagen synthesis. To know the gene expression of type II collagen, dot blot hybridization was performed using type II collagen cDNA. The effects of NSAIDs on the amount of type II collagen mRNA were consistent with those on collagen biosynthesis. Thus, TA had the least effect on cultured chondrocytes.