title: Subchronic administration of caffeine and theophylline in drinking water: effects on rat liver RNA polymerase I activity.
abstract: Administration of caffeine or theophylline, 0.2 mg/ml (an average of 20 mg/kg/d) of drinking water, to male CD rats, 2 months of age, over a 15 week period resulted in the elevation of liver RNA polymerase I activity by 2-3 fold as assayed in isolated nuclei. This increase in activity was already apparent by the fourth week of exposure. The changes in RNA polymerase I activity were accompanied by moderate liver hypertrophy.
mesh_terms: D000818:Animals; D002110:Caffeine / Q000633:toxicity*; D012321:DNA-Directed RNA Polymerases / Q000032:analysis*; D004326:Drinking / Q000187:drug effects; D006984:Hypertrophy; D008099:Liver / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D008297:Male; D012318:RNA Polymerase I / Q000032:analysis*; D051381:Rats; D011919:Rats, Inbred Strains; D013806:Theophylline / Q000633:toxicity*
chemical_list: D002110:Caffeine; D013806:Theophylline; D012321:DNA-Directed RNA Polymerases; D012318:RNA Polymerase I