Interleukin 1β (IL-1β) modulated glycosaminoglycan (GAG) synthesis and UDP-glucose dehydrogenase ( UGDH ) gene expression. Human articular chondrocytes were treated with recombinant IL-1β for 12 h, 24 h and 48 h. Then, GAG content (A) and the mRNA level of UGDH (B) of chondrocyte cultures was detected. Meanwhile, UGDH protein level from chondrocytes treated with IL-1β for 48 h was detected using western blotting assay (C, D). Values were presented as mean ± standard error of the mean from at least three independent experiments. *P <0.05 and **P <0.01 versus control.