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)