ABSTRACT
Previous studies have demonstrated that the nitric oxide [NO] dependent death of murine peritoneal macrophages activated in vitro with IFN- gamma and LPS is mediated through apoptosis. In the present study, we investigated the synergistic effect of LPS, IFN- gamma and iron on NO production and apoptosis. After determination of iron cytotoxicity, the peritoneal macrophages of Balb/c mice were cultured with iron, LPS, and IFN- gamma separately, or a mixture of these for 18 hr at 37 C, Then after 18 hr incubation, the level of NO in supernatant was measured by the Griess method. At the same time, after incubation with ethidium bromide and acridine orange dye, the apoptotic macrophages were detected by fluorescence microscopy. NO production was significantly greater than the control group in macrophages exposed to iron, LPS, or IFN- gamma alone [P=0.02], while no significant difference was detected in apoptosis rate in the presence of LPS [.P=0.08]. However, the differences were remarkable between NO production and apoptosis rate in the presence of iron, LPS and IFN- gamma [P