Persistence of benzo[a]pyrene-DNA adducts in hematopoietic tissues and blood of the mummichog, Fundulus heteroclitus

The formation and persistence of benzo[a]pyrene (B[a]P)-DNA adducts were in vestigated in blood, liver and two hematopoietic tissues (anterior kidney a nd spleen) of the mummichog (Fundulus heteroclitus). Fish were injected wit h a single, sublethal dose of B[a]P (12 mg/kg body weight) and sampled from 8 to 96 days post-injection. P-32-Postlabeling analysis and storage phosph or imaging were used to resolve and quantify hydrophobic DNA adducts. One m ajor DNA adduct was present in each of the examined tissues at all sampling times. This adduct had similar chromatographic characteristics to those of the adduct standard, 7R,8S,9S-trihydroxy-10S-(N-2-deoxyguanosyl-3'-phospha te)-7,8,9,10-tetrahydro-benzo[a]pyrene (B[a]PDE-dG). Minor DNA adduct spots , representing less than 2% of the total DNA adducts, were observed in some liver, anterior kidney and spleen samples for up to 32 days post-injection . The B[a]P-DNA adducts reached maximal levels at 32 days post-injection an d persisted for at least 96 days in all examined tissues. B[a]P-DNA adduct levels were significantly higher in the liver and anterior kidney than in t he spleen from 16 to 96 days (P < 0.001), although liver and anterior kidne y DNA adduct levels were not significantly different at any time. This is t he first controlled study to demonstrate the formation and persistence of B [a]P-DNA adducts in hematopoietic tissues and blood of fishes exposed to th e prototypical polycyclic aromatic hydrocarbon, B[a]P. Although persistent DNA adducts are generally recognized as potential initiators of carcinogeni c processes, adducts in these vital tissues may also lead to disruption of physiological functions such defense mechanisms and hematopoiesis. (C) 2001 Elsevier Science B.V. All rights reserved.