title: Organ-specific promoting effects of phenobarbital sodium and sodium saccharin in the induction of liver and urinary bladder tumors in male F344 rats.
abstract: Studied were conducted to determine whether initial treatment with N-2-fluorenylacetamide (2-FAA) or N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) followed by treatment with either phenobarbital sodium (PB) or sodium saccharin (SS) induced or enhanced liver and/or bladder tumorigenesis. Male inbred F344 rats were given 0.05% PB and 5.0% SS in the diet for 32 weeks after 4-week administration of 0.02% 2-FAA treatment and induced hyperplastic liver nodules after BBN treatment. The SS significantly enhanced induction of bladder hyperplasias, but not papilloma after BBN treatment, and induced bladder hyperplasias after 2-FAA treatment. However, PB had no effect on the bladder and SS had no effect on the liver after either 2-FAA or BBN treatment. The data indicate that although 2-FAA and BBN have tumor-initiating effects in the liver and urinary bladder, the tumor-promoting effects of PB and SS are organ-specific. The tumor-promoting effect of PB for the liver is relatively greater than that of SS for the urinary bladder.
mesh_terms: D015073:2-Acetylaminofluorene / Q000633:toxicity; D000818:Animals; D002085:Butylhydroxybutylnitrosamine / Q000633:toxicity; D003043:Cocarcinogenesis; D006965:Hyperplasia / Q000139:chemically induced; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced*; D008297:Male; D009374:Neoplasms, Experimental / Q000139:chemically induced; D009928:Organ Specificity; D010634:Phenobarbital / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D011916:Rats, Inbred F344; D012439:Saccharin / Q000378:metabolism / Q000494:pharmacology*; D001743:Urinary Bladder / Q000473:pathology; D001749:Urinary Bladder Neoplasms / Q000139:chemically induced*
chemical_list: D002085:Butylhydroxybutylnitrosamine; D015073:2-Acetylaminofluorene; D012439:Saccharin; D010634:Phenobarbital