Effect of Y-27632 treatment on neutrophil apoptosis. Mice were injected with PBS or LPS (250 ng/cavity, i.pl.) and, 4 h later, received a local injection (i.pl.) of Y-27632 (1 or 10 mg/kg, i.pl.) or vehicle. Cells with distinctive apoptotic morphology were evaluated 4 h after drug treatment and are expressed as percent of neutrophils with distinctive apoptotic morphology (A) Representative figures of viable and apoptotic neutrophils (arrow) (B). Scale bar = 10 μm. Original magnifications, ×40. The pan-caspase inhibitor zVAD-fmk (1 mg/kg, i.p.) was given 15 min before ROCK inhibition (Y-27632 10 mg/kg, i.pl.). The number of neutrophils (C), cells with distinctive apoptotic morphology (D) and Western blot to detection of pro-caspase 3 and cleaved caspase-3 (E) were evaluated 4 h after drug treatment. Densitometry analysis of Western blot are shown (F). Results are expressed as the number of cells/cavity and are shown as the mean ± SEM of five mice in each group (ANOVA test followed by Holm-Sidak’s multiple comparison).