title: Toxicokinetics and biotransformation of pentachlorophenol in the topsmelt (Atherinops affinis).
abstract: The toxicokinetics and biotransformation of pentachlorophenol (PCP) were determined in the topsmelt (Atherinops affinis). In a static system, topsmelt (n = 9) were exposed to 50 micrograms/L of [U-14C]PCP for 24 hours to determine the absorption rate constant (Ka), the whole-body bioconcentration (at steady-state conditions), the elimination rate constant (Ke), and the elimination half-life (t1/2). Kinetics were determined by direct quantitation of radioactivity in the exposure water. Following exposure, fish were placed in a flow-through metabolism chamber for 24 hours to allow depuration of retained residues, which were collected on XAD-4 resin. Excreted residues were identified and quantified by high-pressure liquid co-chromatography, fraction collection, and liquid scintillation counting. The Ka and Ke, calculated using a simplified model, were 0.012 +/- 0.005/h and 0.014 +/- 0.003/h, respectively, while the 24 hour total concentration factor was 278.0 +/- 182.0 and the t1/2 was 52.7 +/- 11.2. During 24 hours of exposure to clean seawater, topsmelt depurated 32.9% of retained residues, and while PCP was primarily excreted unchanged (64.9%), significant amounts of both pentachlorophenylsulfate (18.9%) and pentachloro-beta-D-glucuronide (16.2%) were also formed.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Santa Cruz 95064.
authors.forename: D B
authors.initials: DB
authors.lastname: Benner
authors.forename: R S
authors.initials: RS
authors.lastname: Tjeerdema
mesh_terms: D000042:Absorption; D000818:Animals; D001711:Biotransformation; D002851:Chromatography, High Pressure Liquid; D005399:Fishes / Q000378:metabolism*; D006207:Half-Life; D010416:Pentachlorophenol / Q000493:pharmacokinetics* / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D014874:Water Pollutants, Chemical; D010416:Pentachlorophenol