The p38 inhibitors SB-203580 and VX-745 significantly inhibited the severity of iodoacetate-induced knee degeneration in rats. The severity of knee degeneration in rats injected with 0.25 mg of iodoacetate was evaluated 3 weeks after treatment with either vehicle (0.5% carboxymethylcellulose/0.5% Tween 20), 50 mg/kg bid of SB-203580 or VX-745 orally. The data are expressed as the mean ± S.E.M. from 15 rats per treatment group. * denotes P < 0.05.