Figure 1.

Iron enhances paraquat-induced dopaminergic N27 cell apoptosis in vitro. A, N27 cells were treated with increasing concentrations of paraquat and 80 μm FeCl₂ for 24 h. Cell viability was measured via the MTT assay and expressed as a percentage of viability in control. B–F, Cells were treated with EUK-189 1 h before the addition of 80 μm FeCl₂ and 350 μm paraquat and cell viability at 24 h (B), cleaved caspase-3-positive cells at 18 h (C, E), and TUNEL-positive cells at 24 h (D, F) were measured. Error bars indicate mean ± SEM. n = 5. ^#p < 0.01, significantly from control; *p < 0.01, significantly from paraquat; **p < 0.01, significantly from paraquat alone; *** p < 0.01, significantly from paraquat plus FeCl₂ alone. White bar, Paraquat; black bar, paraquat plus FeCl₂.