| Popis: |
Juvenile starry flounder (Platichthys stellatus) were force-fed naphthalene, p-cresol, or a mixture of naphthalene and p-cresol in daily doses of 0.3–0.4 mg/kg body weight, for 6 consecutive days. On the 8th day, each fish was force-fed a dose of 12–15 mg/kg of 2,6-dimethyl[14C]naphthalene (DMN). Twenty-four hours later, the fish were killed and 14C-labelled metabolites in the bile were isolated and identified by thin-layer chromatography. Most of the biliary metabolites were recovered as conjugates, principally as glurosides and glucuronides. Analyses of the nonconjugated metabolites and metabolites resulting from enzymatic hydrolysis of the conjugates provided identification of four metabolites of DMN: 2,6-dimethyl-3-naphthol; 2,6-dimethyl-3,4-naphthoquinone; trans-3,4-dihydroxy-3,4-dihydro-2,6-dimethylnaphthalene (dihydrodiol); and b-methyl-2-naphthalenemethanol (alcohol). Enzymatic hydrolysis of the glucuronides yielded two metabolites: the alcohol, representing metabolism at a methyl substituent, and the dihydrodiol, representing oxidation of an aromatic ring. Exposure to naphthalene and/or p-cresol led to a significant reduction (P |
