Induction by phenobarbital of the mRNA for a specific variant of rat liver microsomal cytochrome P-450.
The treatment of rats for 4 days with phenobarbital causes an apparent 3-fold increase in the amount of total liver cytochrome P-450. By sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, metyrapone binding and immunoprecipitation, this increase was found to be due to a much larger increase in a restricted number of specific cytochrome P-450 variants. A radioimmunoassay technique demonstrated that the major phenobarbital-inducible variant, of molecular weight 52 000, is induced 24-fold by phenobarbital. Immunoprecipitation analysis of products of translation in vitro with an antibody specific to the 52 000-mol.wt. cytochrome P-450 showed that phenobarbital induces the mRNA in polyribosomes for this variant 20-fold. Evidence is presented for the action of phenobarbital at the transcriptional and translational levels.
D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis*; D004591:Electrophoresis, Polyacrylamide Gel; D004790:Enzyme Induction / Q000187:drug effects; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology*; D010634:Phenobarbital / Q000494:pharmacology*; D011132:Polyribosomes / Q000378:metabolism; D014176:Protein Biosynthesis / Q000187:drug effects; D012333:RNA, Messenger / Q000378:metabolism*; D011863:Radioimmunoassay; D051381:Rats
D012333:RNA, Messenger; D003577:Cytochrome P-450 Enzyme System; D010634:Phenobarbital