Prevention of apoptosis by inhibition of caspase-3. PMN were treated for 1 hour at 37°C with 200 μmol/L of the caspase-3 inhibitor Z-DEVD-FMK or left untreated (vehicle) before stimulation for 2 hours with 300 U/mL TNF-, 300 U/mL GM-CSF, or left untreated (control), respectively. Data represent apoptotic PMN in percent of total cell number. Mean ± SD of three independent experiments. *P < .05; n.s., not significant.