title: Comparison of the mutational specificity induced by environmental genotoxin nitrated polycyclic aromatic hydrocarbons in Salmonella typhimurium his genes.
abstract: Mutagenicity of 15 nitrated polycyclic aromatic hydrocarbons (nitro PAHs), which were detected in ambient air particles and/or combustion source emissions, were examined using a set of six Salmonella typhimurium tester strains (TA7001 to TA7006), and the mutational specificity was characterized by the comparison of the mutagenic potencies of nitro-PAHs in the tester strains. Each strain carries a unique missense mutation in the histidine operon and is reverted by only one specific base-substitution out of six possible changes. All nitro-PAHs tested were mutagenic in multiple strains, and were classified into four categories based on the strains predominantly reverted. 1-Nitropyrene (1-NPy), 2,7-dinitrofluoren-9-one and 1,3-, 1,6- and 1,8-dinitropyrene isomers exerted the highest mutagenicity in strain TA7005 (C.G-->A.T transversion) followed by strain TA7006 (C.G-->G.C transversion). 2- And 3-nitrofluoren-9-one isomers, 2-NPy and 2,7-dinitrophenanthrene were also markedly mutagenic in strain TA7005 but not in strain TA7006. For 2-, 3- and 9-nitrophenanthrene isomers, 2-nitrofluoranthene (2-NFT) and 4-NPy, TA7004 (G.C-->A.T transition) was the most responsive strain. 3-NFT was unique, showing the highest mutagenicity in strain TA7002 (T.A-->A.T transversion). All nitro-PAHs tested induced C.G-->A.T transversion, which is observed as the most frequent base-substitution mutation of p53 tumor suppressor gene in human lung cancer.
authors.affiliation: Kyoto Pharmaceutical University, Japan. watanabe@mb.kyoto-phu.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
authors.forename: M
authors.initials: M
authors.lastname: Takashima
authors.forename: T
authors.initials: T
authors.lastname: Kasai
authors.forename: T
authors.initials: T
authors.lastname: Hirayama
mesh_terms: D004785:Environmental Pollutants / Q000633:toxicity*; D006639:Histidine / Q000235:genetics*; D009152:Mutagenicity Tests; D009153:Mutagens / Q000633:toxicity*; D011083:Polycyclic Compounds / Q000633:toxicity*; D012486:Salmonella typhimurium / Q000235:genetics*
chemical_list: D004785:Environmental Pollutants; D009153:Mutagens; D011083:Polycyclic Compounds; D006639:Histidine