title: Rat nasal tissue activation of benzo(a)pyrene and 2-aminoanthracene to mutagens in Salmonella typhimurium.
abstract: Cytochrome P-450-dependent monooxygenase activity has been measured in the nasal turbinates of dogs and rats. The capacity of male Fischer-344 rat nasal tissue to bioactivate benzo(a)pyrene (BaP) and 2-aminoanthracene (2-AA) to mutagens in Salmonella typhimurium was investigated. 2-AA was mutagenic in strains TA98 and TA100 when nasal tissue S-9 was utilized as the activating enzyme system and BaP was mutagenic in strain TA100. At all doses and protein concentrations tested, 2-AA displayed nearly 500-1000 times greater bacterial mutagenicity than BaP. In strain TA-100, nasal tissue S-9 was approximately twice as active toward 2-AA as lung S-9 and 75% as active as liver S-9. Aryl hydrocarbon hydroxylase activity was detected in rat nasal tissue when 14C-BaP was used as a substrate. Rat nasal tissue metabolized BaP to several oxidized metabolites which included dihydrodiols, quinones, and phenols. 3-Hydroxybenzo(a)pyrene and BaP-3, 6-quinone were the major metabolites detected (150 pmoles/mg protein/30 min). These results indicate that rat nasal tissue can metabolize promutagens to reactive species which may play an important role in xenobiotic-induced nasal tumors.
mesh_terms: D000818:Animals; D000873:Anthracenes / Q000378:metabolism* / Q000633:toxicity; D001189:Aryl Hydrocarbon Hydroxylases / Q000378:metabolism; D001564:Benzo(a)pyrene; D001580:Benzopyrenes / Q000378:metabolism* / Q000633:toxicity; D001711:Biotransformation; D004848:Epithelium / Q000378:metabolism; D008297:Male; D008861:Microsomes / Q000378:metabolism*; D009092:Mucous Membrane / Q000378:metabolism; D009152:Mutagenicity Tests; D009153:Mutagens / Q000378:metabolism*; D009154:Mutation; D009297:Nasal Mucosa / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344; D012486:Salmonella typhimurium / Q000187:drug effects
chemical_list: D000873:Anthracenes; D001580:Benzopyrenes; D009153:Mutagens; D001564:Benzo(a)pyrene; C006593:2-anthramine; D001189:Aryl Hydrocarbon Hydroxylases