title: Susceptibility of C57BL/6 mice to tumorigenicity induced by dimethylnitrosamine and 2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine in the neonatal bioassay.
abstract: Male C57BL/6 neonates were treated on days 8 and 15 with 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP, 6.5 or 26.2 mg/kg) or dimethylnitrosamine (DMN, 2.6 or 10.5 mg/kg). No tumors were seen in PhIP-treated animals at 15 months of age. Liver and lung tumor incidences in DMN-treated animals were 67-79 and 0-7%, respectively. In comparison with data from other strains, our results indicate that (1) neonatally-treated C57BL/6 mice are resistant to the induction of liver and lung tumors by PhIP and lung tumors by DMN and (2) the susceptibility of this strain to induced liver tumors correlates with the activity of hepatic DMN N-demethylase and PhIP N-hydroxylase in the (untreated) neonates.
authors.affiliation: Division of Genetic and Reproductive Toxicology, National Center for Toxicological Research, Jefferson, AR 72079, USA.
authors.forename: S B
authors.initials: SB
authors.lastname: Dass
authors.forename: G J
authors.initials: GJ
authors.lastname: Hammons
authors.forename: T J
authors.initials: TJ
authors.lastname: Bucci
authors.forename: R H
authors.initials: RH
authors.lastname: Heflich
authors.forename: D A
authors.initials: DA
authors.lastname: Casciano
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D015197:Carcinogenicity Tests; D002273:Carcinogens / Q000633:toxicity*; D019392:Cytochrome P-450 CYP2E1 / Q000378:metabolism; D004128:Dimethylnitrosamine / Q000633:toxicity*; D004198:Disease Susceptibility; D004305:Dose-Response Relationship, Drug; D007093:Imidazoles / Q000378:metabolism / Q000633:toxicity*; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced* / Q000201:enzymology; D008175:Lung Neoplasms / Q000139:chemically induced* / Q000201:enzymology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D006899:Mixed Function Oxygenases / Q000378:metabolism
chemical_list: D002273:Carcinogens; D007093:Imidazoles; C049584:2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine; D006899:Mixed Function Oxygenases; D019392:Cytochrome P-450 CYP2E1; D004128:Dimethylnitrosamine