Mouse interferon gamma pretreated hepatocytes conditioned media suppress cytochrome P-450 induction by TCDD in mouse hepatoma cells.
Mouse interferon gamma (IFN-G) markedly suppressed 7-ethoxyresorufin o-deethylase (EROD) activity when added at the same time as TCDD in mouse primary hepatocyte cultures. IFN-G, however, had no effect on EROD induction by TCDD in Hepa-1 cells, a mouse hepatoma cell line, or Hepa-1 cells cocultured with Kupffer cells when added directly to the culture. EROD induction by TCDD in Hepa-1 cells was suppressed when cells were cultured with IFN-G pretreated mouse hepatocytes conditioned media. The magnitude of suppression was related to the dose of IFN-G and the density of hepatocytes used for the preparation of the conditioned media. Treatment of the monoclonal antibody against IFN-G to the conditioned media did not block the suppression of EROD induction. The suppressive effect of IFN-G pretreated hepatocytes conditioned media on EROD induction, however, was blocked when the conditioned media was heated or treated with trypsin. These results suggested that IFN-G pretreated mouse hepatocytes may release a soluble protein factor(s) which suppressed the EROD induction by TCDD in Hepa-1 cells.
Department of Life Science, Korea Advanced Institute of Science and Technology, Taejon.
H G
HG
Jeong
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TC
Jeong
K H
KH
Yang
D000818:Animals; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D019363:Cytochrome P-450 CYP1A1; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D004790:Enzyme Induction; D007371:Interferon-gamma / Q000494:pharmacology*; D007728:Kupffer Cells / Q000502:physiology; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D008114:Liver Neoplasms, Experimental / Q000201:enzymology*; D051379:Mice; D010088:Oxidoreductases / Q000096:biosynthesis*; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D017077:Culture Media, Conditioned; D000072317:Polychlorinated Dibenzodioxins; D007371:Interferon-gamma; D003577:Cytochrome P-450 Enzyme System; D010088:Oxidoreductases; D019363:Cytochrome P-450 CYP1A1