Proliferation assay with selective and unselective cyclooxygenase (COX) inhibitors. The effect of selective and unselective COX inhibitors on chondrocyte proliferation was assessed by [3H]-thymidine incorporation. Subconfluent chondrocytes were synchronized in serum-free medium for 24 hours. Medium was renewed and the indicated inhibitors were added for 24 hours: indo, 50 μM indomethacin; SC-560, 10 μM; SC-236, 10 μM. Data are given as mean ± standard error of the mean, n = 6; *p value < 0.05.