Induction by phenobarbital in McA-RH7777 rat hepatoma cells of a polycyclic hydrocarbon inducible cytochrome P450.
The metabolism of 2-acetylaminofluorene (AAF) to its six oxidative metabolites has been used to study cytochrome P450 monooxygenase activity in two rat hepatoma cell lines, McA-RH7777 and Reuber H4-II-E. McA-RH7777 cells exhibited considerably higher basal activities than H4-II-E cells for all metabolic pathways studied. Phenobarbital induced AAF metabolite formation in McA-RH7777 cells to a similar extent as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), but was only a weak inducer of these activities in H4-II-E cells. Northern blot analysis utilizing specific phenobarbital or 3-methylcholanthrene inducible cytochrome P450 cDNA probes indicated that there was at least a 10-fold increase in a 3-methylcholanthrene inducible cytochrome P450 transcript in phenobarbital treated McA-RH7777 cells. These data suggest that in this transformed cell line phenobarbital behaves as a polycyclic hydrocarbon-like inducer.
D015073:2-Acetylaminofluorene / Q000378:metabolism; D000818:Animals; D001140:Aroclors / Q000494:pharmacology; D002460:Cell Line; D020111:Chlorodiphenyl (54% Chlorine); D003001:Cloning, Molecular; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D004790:Enzyme Induction / Q000187:drug effects; D008114:Liver Neoplasms, Experimental / Q000201:enzymology; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D009693:Nucleic Acid Hybridization; D010634:Phenobarbital / Q000494:pharmacology*; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology; D011083:Polycyclic Compounds / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats
D001140:Aroclors; D000072317:Polychlorinated Dibenzodioxins; D011083:Polycyclic Compounds; D012333:RNA, Messenger; D020111:Chlorodiphenyl (54% Chlorine); D003577:Cytochrome P-450 Enzyme System; D015073:2-Acetylaminofluorene; D006899:Mixed Function Oxygenases; D010634:Phenobarbital