Dexamethasone dose-respose studies. A) Effect of DEX on TNFα-stimulated GAG loss in bovine cartilage explants. Cartilage tissues were cultured in DEX (0.1 nM-100 μM)-supplemented media, with or without TNFα (25 ng/ml) for six days. The total GAG content of untreated control cartilage was 465.6 ± 23.1 μg GAG/disk (mean ± SEM). DEX, at 1 nM and higher reduced GAG loss induced by TNFα treatment. B) Effect of DEX on chondrocyte biosynthetic rates as measured by 35S-sulfate incorporation during days 4 to 6. TNFα treatment significantly lowered biosynthesis of sulfated proteoglycans; DEX reversed this inhibition at concentrations of 0.1 nM or higher. Values in A and B are presented as mean ± SEM; n = 5 cartilage disks per condition. *= P < 0.05 vs. no-treatment control. DEX, dexamethasone; GAG, glycosaminoglycans; SEM, standard error of the mean; TNFα, tumor necrosis factor alpha.