The levels of
aromatic hydrocarbons in sediments of Puget Sound, Washington, are positively correlated with the prevalence of
hepatic neoplasms and related lesions in English sole (Parophrys vetulus). To investigate the biochemical processes involved in chemical
carcinogenesis in fish from Puget Sound, we have studied the uptake, activation, and detoxication of
polycyclic aromatic hydrocarbons (PAHs) in English sole, and have compared these data to PAH metabolism in a related species, starry flounder (Platichthys stellatus), which shows a lower prevalence of
hepatic neoplasms than sole. The results of both laboratory and field studies show that sediment-associated PAHs are biologically available to both flatfish species, and that both species accumulate similar levels of PAHs. Analyses of hepatic
DNA from sole using the 32P-postlabeling technique indicate that
xenobiotic chemicals were adducted to hepatic
DNA of fish from the contaminated sites but not to the
DNA of fish from reference sites. Studies of the ability of English sole and starry flounder to metabolize
benzo(a)pyrene (BaP) and bind reactive BaP intermediates to hepatic
DNA indicate that biochemical differences in the metabolism of carcinogenic PAHs may explain, at least in part, the apparent lower susceptibility of starry flounder than English sole to chemically induced hepatocarcinogenesis.