This study was carried out to investigate the effect of long-term exposure to
benzo(a)pyrene (B(a)P) in mice. Hemogram, tumor markers, oxidative status, and
B(a)P residues in liver tissue were evaluated. Sixty albino Swiss mice were
randomly distributed equally into three groups; the control was given 0.1 mL corn
oil once a week for 8 weeks. The other two groups were given 20 and 40 mg B(a)P
per kg body weight once a week orally for the same period. B(a)P-treated mice
suffered from depression and ascites, and macrocytic normochromic anemia was
recorded at the 16th and 30th week. There was marked leukocytosis with
lymphocytosis at the early stage of the experiment, followed by leukopenia,
lymphopenia, and neutropenia at the end of the experiment. Monocytes and
arginase activity were elevated throughout the experiment. Alpha feto-protein
was detected only in the experimental groups in the 30th week of the experiment.
A marked increase in lipid peroxides associated with a decrease in reduced
glutathione and glutathione-S-transferase (GST) activity was observed in liver
homogenate of the B(a)P-exposed animals. Residues of B(a)P were detected in
liver tissue with a concentration parallel to the B(a)P dose level. In conclusion,
B(a)P caused abnormal changes in the hemogram, evidence of tumor formation
through B(a)P-induced oxidative stress, and it was accumulated in the liver tissue
of mice.