title: Hormonal stimulation of 3H-orotic acid incorporation into RNA by serum-free cultured hepatocytes.
abstract: Insulin and dexamethasone greatly stimulate the incorporation of 3H-orotic acid into RNA. Such a stimulation is associated to an increase in the uptake of the labelled precursor into the acid soluble fraction as well as in the the specific radioactivity of the nucleoside plus nucleotide pool suggesting that hormone supplementation does not affect RNA synthesis by cultured cells. The lack of effect of insulin and dexamethasone on the level of total RNA polymerase activity in nuclei isolated from cultured hepatocytes is in line with this assumption. The hormone stimulated uptake of orotic acid is dependent on protein synthesis since it is completely abolished by cycloheximide.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology; D006728:Hormones / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D009963:Orotic Acid / Q000378:metabolism*; D014176:Protein Biosynthesis; D012313:RNA / Q000096:biosynthesis*; D051381:Rats; D013997:Time Factors
chemical_list: D006728:Hormones; D007328:Insulin; D009963:Orotic Acid; D012313:RNA; D003907:Dexamethasone