title: Complexity of liver mRNA from normal and thioacetamide-treated rats.
abstract: The complexity and diversity of polysomal poly(A)-containing RNA (mRNA) isolated from livers of normal and thioacetamide (TAA)-treated rats were compared by mRNA/complementary DNA hybridization technique. Three kinetic components (frequency classes) representing in normal mRNA about: I-34, II-32 and III-34% of RNA, apparently contained about 3, 60 and 3400 different sequences of 1 kb each, respectively. The corresponding values for mRNA from TAA-treated rats were about: I-24, II-36, and III-40%, comprising about 1, 30 and 3200 different sequences. It appeared that abundant mRNA sequences (from components I and II) may be 2-5 times more frequently represented in mRNA from TAA-treated than from normal rats. About 15% of mRNA sequences in TAA-treated rats were apparently transcribed from repetitive DNA reassociated to a Cot of 100. The results suggested that thioacetamide, a potent hepatocarcinogen, modulates the transcription or post-transcription regulatory steps of a few selected mRNA species, leading to their accumulation in the cell.
mesh_terms: D000081:Acetamides / Q000494:pharmacology*; D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism; D004247:DNA; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D009693:Nucleic Acid Hybridization; D011061:Poly A / Q000378:metabolism; D011132:Polyribosomes / Q000378:metabolism; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013853:Thioacetamide / Q000494:pharmacology*
chemical_list: D000081:Acetamides; D012333:RNA, Messenger; D013853:Thioacetamide; D011061:Poly A; D012313:RNA; D004247:DNA