Troglitazone, but not 15d-PGJ₂, decreases polarization and actin polymerization in response to fMLP. PMNs were pretreated with troglitazone (5 or 10 μM) or with 15d-PGJ₂ (5 or 10 μM) for 2 hours, then stimulated with fMLP (10⁻⁷ M) for 10 minutes. (A) Cells were stained with TRITC-phalloidin, and confocal microscopy was used to analyze F-actin distribution and morphologic changes. Results shown are representative of 3 independent experiments. All panels depict stimulation with fMLP except control (Ctrl). (B) The change in F-actin content is expressed as a relative fold change in mean fluorescence intensity, with the fluorescence intensity of unstimulated control cells set as 1. *P < .05 compared to DMSO-treated cells. Tro indicates troglitazone; PGJ₂, 15-deoxy-Δ^12,14-prostaglandin J₂. Error bars represent SEM.