cDNA cloning and analysis of chick-embryo-liver cytochrome P-450 mRNA induced by porphyrinogenic drugs.
Hepatic microsomal cytochrome P-450 was elevated in 17-day chick embryos by combined administration of the porphyrinogenic drugs 2-allyl-2-isopropylacetamide and 3,5-diethoxycarbonyl-1,4-dihydrocollidine. Increased apoprotein levels were the result of de novo protein synthesis; in vitro obtained translation data suggested that cytochrome P-450 mRNA levels were elevated. A 1000-base cDNA sequence for the drug-induced cytochrome P-450 mRNA was isolated from a chick embryo cDNA 'library' and this was used as a specific probe to investigate drug-mediated induction of cytochrome P-450 mRNA. RNA-DNA 'dot' hybridisation studies demonstrated that drug treatment led to a 3-5-fold increase in the level of this mRNA and that the mRNA was predominantly associated with membrane-bound polyribosomes. Treatment of embryos with the drugs individually demonstrated that both of them induced synthesis of the same mRNA. These studies show directly that treatment of chick embryos with 2-allyl-2-isopropylacetamide or 3,5-diethoxycarbonyl-1,4-dihydrocollidine caused increased levels of cytochrome P-450 mRNA and suggest that this involved increased transcription of the gene.
D000081:Acetamides / Q000494:pharmacology*; D000502:Allylisopropylacetamide / Q000494:pharmacology*; D000818:Animals; D002642:Chick Embryo; D003001:Cloning, Molecular; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis* / Q000235:genetics; D004247:DNA / Q000302:isolation & purification*; D003997:Dicarbethoxydihydrocollidine / Q000494:pharmacology*; D005796:Genes / Q000187:drug effects; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology*; D009693:Nucleic Acid Hybridization; D011164:Porphyrias / Q000139:chemically induced; D014176:Protein Biosynthesis / Q000187:drug effects; D011725:Pyridines / Q000494:pharmacology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000302:isolation & purification*
D000081:Acetamides; D011725:Pyridines; D012333:RNA, Messenger; D000502:Allylisopropylacetamide; D003997:Dicarbethoxydihydrocollidine; D004247:DNA; D003577:Cytochrome P-450 Enzyme System