title: Alteration in the ribonucleic acids in rat liver induced by a methionine-free total parenteral nutrition solution.
abstract: The effect of infusion of a methionine-free total parenteral nutrition solution for 7 d on ribonucleic acids in liver of rats were investigated. The control solution contained leucine, valine, isoleucine, lysine, phenylalanine, threonine, tryptophan, arginine, histidine, glycine, methionine, glucose and vitamins and minerals. Deprivation of a methionine is known to increase the activity of RNA polymerase I. Infusing the methionine-free solution resulted in the accumulation of RNA molecules larger than 28S in the liver nuclei and resulted in a higher rate of rRNA synthesis than in rats infused with the control solution. A methionine deficiency did not impede either the processing of 45S pre-rRNA or transport of 28S and 18S rRNA into cytoplasm. When rats were infused with the methionine-free solution for 7 d followed by the control solution for 2 d, the level of RNA in the nucleus as well as the rate of RNA polymerase I were similar to the levels in rats receiving the control solution for 9 d. There were no significant changes in the rate of DNA synthesis due to nutritional manipulations.
mesh_terms: D000818:Animals; D001835:Body Weight; D002466:Cell Nucleolus / Q000201:enzymology; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004247:DNA / Q000096:biosynthesis; D004591:Electrophoresis, Polyacrylamide Gel; D008099:Liver / Q000378:metabolism* / Q000648:ultrastructure; D008297:Male; D008715:Methionine / Q000097:blood / Q000172:deficiency*; D009929:Organ Size; D012313:RNA / Q000096:biosynthesis*; D012318:RNA Polymerase I / Q000032:analysis; D051381:Rats
chemical_list: D012313:RNA; D004247:DNA; D008715:Methionine; D012318:RNA Polymerase I