In vitro metabolism andin vivo binding of benzo(a)pyrene in the California killifish (Fundulus parvipinnis) and speckled sanddab (Citharicthys stigmaeous)

Abstract

Aquatic species in the nearshore environment are exposed to potentially carcinogenic and toxic hydrocarbon pollutants. The pathogenic activity of many of these hydrocarbons is frequently dependent upon host metabolic activation and deactivation patterns. To better understand the potential hazard of these substances to aquatic species, thein vitro metabolism andin vivo binding of the ubiquitous hydrocarbon pollutant benzo(a)pyrene (BaP) were studied in an estuarine fish (Fundulus parvipinnis) and in a benthic marine fish (Citharicthys stigmaeous) and compared to BaP metabolism and binding in mice. While significant amounts of the proximate carcinogen 7,8-di-hydro-7,8-dihydroxybenzo(a)pyrene were produced by the hepatic microsomes of both fish species, total binding of BaP to hepatic DNAin vivo was significantly less in both aquatic species compared to hepatic DNA binding in C57B1/6J mice. The binding of BaP to hepatic proteins ofC. stigmaeous, however, was greater than its binding to proteins in C57B1/6J mice. These findings suggest that this fish may be more resistant than mammalian species to the carcinogenic effects of BaP, but that they may be more sensitive to a variety of toxic effects potentially more damaging to a species than cancer which are also caused by polycyclic aromatic hydrocarbons.