SB-203580 inhibited the severity of iodoacetate-induced knee degeneration in rats in a dose related manner. The severity of knee degeneration in rats injected with 0.25 mg of iodoacetate was evaluated 3 weeks after treatment with vehicle or various doses of SB-203580. The data are expressed as the mean ± S.E.M. from 15 rats per treatment group. * denotes P < 0.05.