title: Tumorigenicity of nitrated derivatives of pyrene, benz[a]anthracene, chrysene and benzo[a]pyrene in the newborn mouse assay.
abstract: Eight nitropolycyclic aromatic hydrocarbons (PAHs), including 1- and 4-nitropyrene, 1,3-, 1,6- and 1,8-dinitropyrene, 7-nitrobenz[a]anthracene, 6-nitrochrysene and 6-nitrobenzo-[a]pyrene and their parent PAHs were tested fro tumorigenicity in the newborn mouse model by i.p. administration at 1, 8, and 15 days after birth. Both pyrene and 1-nitropyrene induced similar incidences of hepatic tumors in males, yielding a 12-15% and a 21-28% tumor incidence at total doses of 700 and 2800 nmol per mouse, respectively. Liver tumors did not occur in females and the 3-10% lung tumor yield in both sexes was similar to that found in solvent-treated controls. The presumed proximate carcinogen, 1-nitrosopyrene, administered at 700 nmol per mouse, caused liver tumors in 45% of the males and in 9% of the females. 4-Nitropyrene was more tumorigenic than pyrene or 1-nitropyrene; at a dose of 2800 nmol, it induced liver tumors in 83% of the males and 7% of the females, with a lung tumor yield of 38 and 31%, respectively. Female mice treated with 200 nmol of 1,3-, 1,6- or 1,8-dinitropyrene did not develop liver tumors but the hepatic tumor incidence in males was 20, 32 and 16%, respectively, which was significantly greater than that found in mice treated with pyrene. In male mice administered 2800 nmol of benz[a]anthracene, the hepatic tumor incidence was 79%, while treatment with 7-nitrobenz[a]anthracene showed an incidence of only 28%. Similarly, 560 nmol of benzo[a]pyrene caused a 49% liver tumor yield in males while those given 6-nitrobenzo[a]pyrene had a 28% incidence. Treatment with benzo[a]pyrene also induced a 35 and 48% lung tumor incidence in males and females while the comparable values in 6-nitrobenzo[a]pyrene-treated mice were 14 and 2%. Chrysene administered at 2800 nmol per mouse induced hepatic and lung tumors in 41% and 21% of the males, respectively; at the 700-nmol dose, it induced only liver tumors in 29% of the males and in none of the females. In contrast, treatment with 6-nitrochrysene at 700 nmol per mouse resulted in a 76 and 23% hepatic tumor incidence in males and females, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001551:Benz(a)Anthracenes / Q000633:toxicity*; D001564:Benzo(a)pyrene; D001711:Biotransformation; D002273:Carcinogens / Q000378:metabolism; D002911:Chrysenes / Q000633:toxicity*; D005260:Female; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced; D008175:Lung Neoplasms / Q000139:chemically induced; D008223:Lymphoma / Q000139:chemically induced; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009374:Neoplasms, Experimental / Q000139:chemically induced*; D009574:Nitro Compounds / Q000633:toxicity*; D010616:Phenanthrenes / Q000633:toxicity*; D011247:Pregnancy; D011721:Pyrenes / Q000633:toxicity*; D013329:Structure-Activity Relationship
chemical_list: D001551:Benz(a)Anthracenes; D002273:Carcinogens; D002911:Chrysenes; D009574:Nitro Compounds; D010616:Phenanthrenes; D011721:Pyrenes; D001564:Benzo(a)pyrene