Glutathione-dependent defense in channel catfish (Ictalurus punctatus) and brown bullhead (Ameriurus nebulosus).

Published

Journal Article

Glutathione-dependent defense against xenobiotic toxicity is a multifaceted phenomenon that has been well characterized in mammals. This study undertakes a comparison of two benthic fish species, the channel catfish and brown bullhead, in terms of characteristics of the glutathione system. The channel catfish, a species that has seldom been observed to express pollutant-mediated neoplasia in field studies, was observed to have significantly higher constitutive levels of hepatic total glutathione and reduced glutatione (GSH). Brown bullhead, a species that is often observed to express neoplasia in contaminated systems, had significantly higher hepatic levels of glutathione disulfide. Furthermore, catfish expressed higher levels of activity of the enzymes gamma-glutamylcysteine synthetase (GCS), glutathione reductase (GR), and glutathione S-transferase, whereas bullhead expressed higher hepatic glutathione peroxidase (GPOX) activity. Both species responded to treatment with the redox active quinone, menadione, by expressing elevated hepatic content of total glutathione. However, the induction response was more rapid and more extensive in catfish compared to that in bullhead. This is attributable to the observed interspecific difference in GCS activity. Following treatment with the organic peroxide, tert-butyl hydroperoxide (t-BOOH), bullhead hepatic glutathione was depleted up to 4 hr post-treatment, whereas catfish demonstrated no significant depletion of glutathione in response to t-BOOH. The differing responses to t-BOOH are attributable to interspecific differences in hepatic GPOX and GR activity. Bullhead, therefore, appear to be more susceptible to the effects of GSH arylators and oxidants based upon constitutive levels of glutathione, related enzyme activities, and the response of this system to model xenobiotics.(ABSTRACT TRUNCATED AT 250 WORDS)

Full Text

Duke Authors

Cited Authors

  • Hasspieler, BM; Behar, JV; Di Giulio, RT

Published Date

  • June 1, 1994

Published In

Volume / Issue

  • 28 / 1

Start / End Page

  • 82 - 90

PubMed ID

  • 7523070

Pubmed Central ID

  • 7523070

Electronic International Standard Serial Number (EISSN)

  • 1090-2414

International Standard Serial Number (ISSN)

  • 0147-6513

Digital Object Identifier (DOI)

  • 10.1006/eesa.1994.1036

Language

  • eng