Impact of copper on biomonitoring enzyme ethoxyresorufin-o-deethylase in cultured catfish hepatocytes.
The enzyme ethoxyresorufin-o-deethylase (EROD) of the cytochrome P4501A family (CYP1A) in fish liver is increasingly being used as a molecular marker for qualitative and quantitative estimation of aquatic pollution throughout the world. The regulation and expression of this enzyme protein is very important from the toxicological point of view. The regulation of gene expression for this enzyme is mediated by the aromatic hydrocarbon receptor. In addition, cellular glutathione status influences expression of CYP1A. In this study, we explored the relationships among glutathione, EROD, and copper in cultured hepatocytes from Indian catfish. EROD activity in cultured hepatocytes was induced by carbofuran (CF), a widely used agricultural pesticide, and by beta-napthoflavone (BNF), a known inducer of CYP1A. Addition of copper into the culture media of hepatocytes inhibited EROD activity significantly. The activity of EROD elevated by CF and BNF was inhibited in hepatocytes pretreated with CF and BNF exposed to CuSO4. This effect was reflected in the glutathione status of the cells. The level of glutathione was increased by 3.4 and 3.0 times in hepatocytes treated with CF and BNF, respectively. These levels were inhibited in hepatocytes exposed to CuSO(4). Thus, copper interactions with glutathione may play a role in regulating EROD in hepatocytes.
Ghosh
M C
MC
Department of Animal Physiology, Bose Institute, P-1/12 CIT Scheme VII M, Calcutta, 7009 054, India.
Ghosh
R
R
Ray
A K
AK
D000818:Animals; D002397:Catfishes / Q000502:physiology*; D018929:Cell Culture Techniques; D003300:Copper / Q000009:adverse effects*; D019363:Cytochrome P-450 CYP1A1 / Q000187:drug effects / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005978:Glutathione / Q000032:analysis; D022781:Hepatocytes / Q000187:drug effects / Q000201:enzymology; D014873:Water Pollutants / Q000009:adverse effects*
D014873:Water Pollutants; D003300:Copper; D019363:Cytochrome P-450 CYP1A1; D005978:Glutathione