Interleukin (IL)-1β produces cartilage degradation characterised by the release of sulphated glycosaminoglycan (sGAG). Temporal increase in cumulative sGAG release for untreated control explants and those cultured in the presence of 10 ng.ml-1 interleukin. Values represent the median cumulative sGAG released from explants during the treatment period of 120 hours. Error bars indicate interquartile ranges. The sGAG release from IL-1-treated explants was statistically greater than that from untreated control explants at all time points (P < 0.001, n = 20; Mann-Whitney U test).