The effects of inhibitors of female sex hormones on neutrophil apoptosis. Neutrophils (1 × 10⁶ cells/mL) were incubated with estradiol, progesterone, or both (10^-7 g/mL) for 24 hours. RU486 (RU; 10^-6 M) was added at time 0 hours and percentage apoptosis was assessed by flow cytometry at 24 hours (n = 11). ICI 182 780 (ICI; 10^-8 M) was added at time 0 hours and percentage apoptosis was assessed by flow cytometry at 24 hours following propidium iodide staining (n = 8). All experiments used both male and female subjects. *P < .05 versus control; **P < .05 versus estradiol; ***P < 0.05 versus progesterone (mean ± SEM).