title: Nitrofurantoin inhibition of mouse liver mitochondrial respiration involving NAD-linked substrates.
abstract: In our study, nitrofurantoin (NF) and nitrofurazone (NZ) inhibited respiration of isolated mouse (C57B/6J, adult, male) liver mitochondria. Other aromatic nitro compounds, nitroimidazole, metronidazole, and p-nitrobenzoic acid, did not have any significant effect. The primary site of activity for NF was complex I NADH-ubiquinone oxidoreductase mediated respiration, since only complex I substrates, glutamate, beta-hydroxybutyrate, and alpha-ketoglutarate-mediated respiration were decreased. Respiration supported by succinate, a complex II substrate, was not affected by any of the compounds. NF at a concentration of 50 microM decreased state 3 and dinitrophenol-uncoupled respiration to 28 +/- 1 and 25 +/- 5% of control, respectively, of mitochondria oxidizing glutamate. Studies with mitoplasts oxidizing glutamate showed that NF inhibited both state 3 and 4 respiration. The inhibition of state 3 was prevented by the simultaneous addition of superoxide dismutase (240 micrograms/ml) and catalase (200 micrograms/ml). These results suggest that the mitochondrion, in particular complex I of the electron transport system, is a target for NF toxicity. The effect on respiration may be mediated by NF redox cycling and the generation of reactive oxygen intermediates resulting in the interference of electron flow.
mesh_terms: D000818:Animals; D002374:Catalase / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008930:Mitochondria, Liver / Q000187:drug effects* / Q000378:metabolism; D009574:Nitro Compounds / Q000494:pharmacology; D009582:Nitrofurantoin / Q000494:pharmacology*; D010084:Oxidation-Reduction; D010085:Oxidative Phosphorylation; D010101:Oxygen Consumption / Q000187:drug effects*; D013379:Substrate Specificity; D013482:Superoxide Dismutase / Q000494:pharmacology
chemical_list: D009574:Nitro Compounds; D009582:Nitrofurantoin; D002374:Catalase; D013482:Superoxide Dismutase