DNA adducts in liver and leukocytes of flounder (Platichthys flesus) experimentally exposed to benzo

In the present study the levels of hydrophobic DNA adducts detected by 32P-postlabelling were followed in liver and leukocytes of flounder (Platichthys flesus) over 10 days following single i.p. injections of two doses of BaP (10 and 50 mg kg(-1) fish weight, respectively). DNA adducts were detected in both tissues of exposed fish 2 days post injection and continued to rise on day 5 and day 10. In flounder exposed to the lower dose of BaP, the levels of hepatic DNA adducts reached higher values on the fifth day compared with flounder exposed to the higher dose. However, at the end of the experiment, the DNA adduct level was again higher in fish from the high dose group compared with the low dose group. There was no substantial increase of DNA adducts in liver of flounder from the low dose group after day 5, while the adduct levels in flounder liver from the high dose group increased throughout the experiment. Earlier studies detecting DNA adducts in BaP-exposed flatfish with the 32P-postlabelling technique have reported declining adduct levels from about 2 days after the exposure, regardless of exposure route. In contrast, the results from our study did not confirm a rapid increase and successive decline of hydrophobic adducts in liver of BaP-exposed flounder.