The effects of URB597 on leukocyte trafficking in the inflamed knee. (A) Time course of the effect of locally administered URB597 (closed circles) vs. vehicle (open circles) on leukocyte rolling. There was a significant reduction in the number of rolling leukocytes after URB597 administration, when compared to vehicle (P <0.0001; two-way ANOVA; n =7 to 11). (B) Dose-response profile of the effect of URB597 on leukocyte rolling 20 min after administration. URB597 (0.3 mg/kg) significantly decreased leukocyte rolling, when compared to vehicle, but this effect was diminished at higher doses. (C) Dose-response profile for the effects of URB597 on leukocyte adhesion 20mins after administration. URB597 (0.3 and 3.0 mg/kg) significantly inhibited leukocyte adhesion, when compared to vehicle; however, this effect was attenuated at higher doses. Data are means ± SEM. *P <0.05, **P <0.01, ***P <0.001 one-way ANOVA with Dunnett's post hoc test vs. vehicle; n =5 to 11. ANOVA, analysis of variance; SEM, standard error of the mean.