Effect of 7,12-dimethylbenz(a)anthracene on the binding of aminoacyl transfer RNA in rat liver.
Homogenates of the liver of female rats obtained 2 or 7 days or 3 months after the i.v. injection of 7,12-dimethylbenz(a)anthracene were used to prepare ribosomes and postmicrosomal supernatant fractions and to prepare 0.5 M KCl salt wash fractions of the 40 S ribosomal subunits. The activity of the ribosomes was unchanged by 7,12-dimethylbenz(a)anthracene. The activity of the supernatant preparation, which contained limiting amounts of Elongation Factor 1 relative to Elongation Factor 2, in peptide synthesis was significantly increased 2 days not 7 days after the injection. Evidence was obtained that this increase was due to increased activity in binding phenylalanyl transfer RNA. The factor-dependent binding of methionyl transfer RNAfMet to control rat liver ribosomes was also markedly increased 2 days but not 7 days after the injection. The liver of animals that bore mammary tumors 3 months after 7,12-dimethylbenz(a)anthracene injection also showed an increase in binding both of the aminoacyl transfer RNA species. The results are discussed in relation to the induction of liver drug-metabolizing enzymes and to liver regeneration.
D015127:9,10-Dimethyl-1,2-benzanthracene / Q000494:pharmacology*; D000818:Animals; D001551:Benz(a)Anthracenes / Q000494:pharmacology*; D003634:DDT / Q000494:pharmacology; D005260:Female; D066298:In Vitro Techniques; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced / Q000378:metabolism; D008715:Methionine / Q000378:metabolism; D010452:Peptide Biosynthesis; D010445:Peptide Elongation Factors; D010448:Peptide Initiation Factors / Q000302:isolation & purification; D010649:Phenylalanine / Q000378:metabolism; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism*; D051381:Rats; D012270:Ribosomes / Q000378:metabolism
D001551:Benz(a)Anthracenes; D010445:Peptide Elongation Factors; D010448:Peptide Initiation Factors; D012346:RNA, Transfer, Amino Acyl; D010649:Phenylalanine; D015127:9,10-Dimethyl-1,2-benzanthracene; D008715:Methionine; D003634:DDT