[Specifics of interaction between benz(a)pyrene and dibenzo(a,l)pyrene with DNA of various mouse tissues]

Fjord-region polycyclic aromatic hydrocarbon (PAH) dibenz (a,l)pyrene (DBP) is the most potent carcinogen in the PAH group. To elucidate the molecular mechanism of the unusual carcinogenic potency of DBP, the levels of DNA adducts in various tissues of the mouse were measured, following an intraperitoneal administration of DBP or a bay-region PAH benz(a)pyrene (BP) in equimolar doses. DBP was found to form much more DNA adducts. While BP formed adducts via fjord-region diol-epoxide formation only, DBP did the same via formation, too. It is suggested that the superior carcinogenic potency of DBP is due to these peculiarities of DNA adduct formation.