Accumulation and metabolism of carbon-14 labeled benzene,naphthalene, and anthracene by young coho salmon (Oncorhynchus kisutch)

Carbon-14 labeled benzene, naphthalene, and anthracene were administered to young coho salmon (Oncorhynchus kisutch) in the food and by intraperitoneal injection. Regardless of the mode of application the accumulated carbon-14 (% administered dose) in key organs (e.g., liver and brain) increased in the order anthracene > naphthalene > benzene over various time periods. The metabolic fate of the hydrocarbons after intraperitoneal injection was studied. It was shown that the highest percentages of metabolites occurred in the gall bladder; however, significant amounts were also found in the liver, brain, flesh, and carcass. Solvent partition and thin-layer chromatographic techniques were developed to determine the structure of individual metabolites. In brain, liver, and gall bladder, 1-naphthol and 1-naphthyl glucuronic acid were major products of naphthalene metabolism; however, glycoside/sulfate fractions and mercapturic acid were indicated. The heart and flesh were rich in 1-naphthol and the former organ contained significant amounts of 1,2-dihydro-1,2-dihydroxynaphthalene. The findings indicated that the aromatic hydrocarbons in key organs increased in relation to the number of benzenoid rings. Further, it appears that aromatic metabolites are broadly distributed throughout fish exposed to polynuclear aromatic hydrocarbons.