Nitrogen monoxide (NO) is a cytotoxic effector molecule produced by macrophages that results in Fe mobilization from tumour target cells which inhibits DNA synthesis and mitochondrial respiration. It is well known that NO has a high affinity for Fe, and we showed that NO-mediated Fe mobilization is markedly potentiated by glutathione (GSH) generated by the hexose monophosphate shunt [Watts, . & Richardson, . (2001) J. Biol. Chem. 276, 4724–4732]. We hypothesized that GSH completes the coordination shell of an NO–Fe complex that is released from the cell. In this report we have extended our studies to further characterize the mechanism.
