Survival of PMNs.

Freshly isolated PMNs as well as cells cultured overnight without additions, with 500 ng/mL G-CSF or with 400 μM zVAD-fmk were stained with annexin-V (x-axis) and PI (y-axis) and were analyzed by FASCscan. Cells without annexin V and PI staining were counted as viable cells (lower left quadrant on each plot). Cell survival was expressed as the percentage of viable cells in the total cell population. (A) Almost all fresh cells were alive. (B) Overnight-cultured untreated cells underwent spontaneous apoptosis. (C,D) Addition of G-CSF or zVAD-fmk, respectively, significantly increased PMN survival (*P < .05 versus untreated cells). Values represent means ± SEM of 8 separate experiments.