NaSal treatment results in the loss of Δψ_mand apoptosis in primary human macrophages. Normal human in vitro—differentiated macrophages were incubated with NaSal (1 mM to 20 mM) for 24 or 48 hours as indicated. (A) The effect of NaSal on Δψ_m (retention of Rh123, mean fluorescence [% of control Rh123]). (B) Cell death induced by NaSal, defined by PI uptake. (C) The effects of NaSal on apoptosis, determined by analysis of subdiploid DNA (< 2N). No indicates no NaSal, or medium control. * indicates P < .05, ** indicates P < .01 determined by Student t test for paired samples compared with no treatment. The results in each panel are presented as the mean ± 1 SE of an experiment performed in triplicate, which is representative of 3 independent experiments.