Chemotactic responses of monocytes to LTD4. A, Chemotactic activity of monocytes to different concentrations of LTD4 or CCL2 (5 nmol/L) as a positive control (Con) was measured as described in the Methods section. LTD4 induces chemotaxis of monocytes in a dose-dependent manner (*P < .001, ANOVA). B, Cells were preincubated with MK571 (MK; 100 nmol/L for 10 minutes), pertussis toxin (PTX; 100 ng/mL overnight), SB203580 (SB35; 5 μmol/L for 30 minutes), SB202190 (SB21; 1 μmol/L for 30 minutes), PD98059 (PD; 10 μmol/L for 30 minutes), and U0126 (10 μmol/L for 30 minutes) and stimulated with LTD4 (100 nmol/L). Data from 3 different donors are presented as the migration index in comparison with vehicle control or percentage of migration index induced by LTD4 (mean ± SD).