Nitrofurantoin-stimulated superoxide production by channel catfish (Ictalurus punctatus) hepatic microsomal and soluble fractions.

Published

Journal Article

Nitroaromatic compounds, which frequently contaminate the environment, are known to be reduced to corresponding aromatic amines by fish as well as mammals under anaerobic conditions. Although amine products are not generally formed aerobically, "nitroreductase"-mediated redox cycling of nitroaromatics may occur under these conditions, leading to enhanced production of a potentially toxic oxygen species, superoxide (O-2). In this study, we have investigated the ability of channel catfish (Ictalurus punctatus) hepatic microsomal and soluble fractions to stimulate O-2) production upon exposure to a model redox cycling nitroaromatic compound, nitrofurantoin (NF). Two assays for O-2 production, cytochrome c reduction and cyanide-insensitive oxygen consumption, were stimulated by NF exposure to both hepatic fractions. These reactions were partially inhibited by superoxide dismutase (SOD), and by SOD and catalase in the oxygen consumption assay, providing specific evidence for the involvement of O-2 in the stimulatory effect by NF. Furthermore, results of cofactor requirement and inhibition studies suggest that NF enhancement of O-2 production was mediated by NADPH-cytochrome P-450 (c) reductase in the microsomal fraction and xanthine oxidase in the soluble fraction. These findings comprehensively suggest that the in vitro stimulation of O-2 production by nitroaromatics as indicated in mammals may also occur in fish and, therefore, suggests a similar potential for oxyradical-mediated toxicities in these species.

Full Text

Duke Authors

Cited Authors

  • Washburn, PC; Di Giulio, RT

Published Date

  • September 1988

Published In

Volume / Issue

  • 95 / 3

Start / End Page

  • 363 - 377

PubMed ID

  • 2847361

Pubmed Central ID

  • 2847361

Electronic International Standard Serial Number (EISSN)

  • 1096-0333

International Standard Serial Number (ISSN)

  • 0041-008X

Digital Object Identifier (DOI)

  • 10.1016/0041-008x(88)90355-9

Language

  • eng