title: RNA metabolism and poly(A) distribution in mouse liver following administration of dimethylnitrosamine.
abstract: Dimethylnitrosamine (DMNA) strongly inhibited RNA synthesis in mouse liver under conditions when the nucleotide pattern, rate of nucleotide synthesis and phosphorylation ratio were unaffected. (An unidentified, probably non-nucleotide, component in the acid-soluble liver fraction was selectively reduced.) The inhibition of RNA synthesis was associated with a decrease in the RNA polymerase activity of isolated liver nuclei, well established already 45 min after DMNA administration. The reduced activity included both Mg2+- and Mn2+/(NH4)2SO4-stimulated polymerase functions. The inhibition in vivo involved the whole complement of RNA, including poly (A)-containing RNA and isolated poly(A) sequences. The transfer of labelled RNA from the nucleus to the cytoplasm was not impaired. There was no detachment of poly(A)-containing RNA from the microsomes, and the proportion of tightly membrane-bound microsomal RNA and poly(A) sequences was not reduced as determined by use of a flotation technique. No breakage or shortening of the poly(A) chains was indicated by sedimentation analysis.
mesh_terms: D000818:Animals; D003593:Cytoplasm / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D004128:Dimethylnitrosamine / Q000494:pharmacology*; D066298:In Vitro Techniques; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D051379:Mice; D008862:Microsomes, Liver / Q000378:metabolism; D009602:Nitrosamines / Q000494:pharmacology*; D009711:Nucleotides / Q000378:metabolism; D011061:Poly A / Q000378:metabolism*; D012313:RNA / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism
chemical_list: D009602:Nitrosamines; D009711:Nucleotides; D011061:Poly A; D012313:RNA; D012321:DNA-Directed RNA Polymerases; D004128:Dimethylnitrosamine