Toxicokinetics and biotransformation of p-nitrophenol in the black turban snail ( Tegula funebralis)

Abstract

An acute study was carried out to determine the toxicokinetics and biotransformation of p-nitrophenol (PNP) in the black turban snail ( Tegula funebralis), an intertidal gastropod mollusc. Snails ( n = 80), in four groups of 20, were exposed to 10 mg/l of [U- 14C]PNP for 24 h in a static chamber in order to measure bioconcentration (total concentration factor, TCF); the absorption rate constant ( K a); the conditional uptake clearance ( K u), which represents the volume of water cleared of PNP per hour; the elimination rate constant ( K e); and the elimination half-life ( t 1 2 ). Following exposure, the snails were transferred to a flow-through metabolism chamber for an additional 24 h. All eliminated residues were collected via Amberlite XAD-7 resin, identified by high-pressure liquid co-chromatography, and quantified by liquid scintillation counting. Using simplified equations, the k a, k u, k e, t 1 2 , and TCF were calculated to be 0.06 ± 0.01/h, 3.28 ± 0.62 ml/g h −1, 0.84 ± 0.10/h, 0.84 ± 0.11h, and 0.13 ± 0.02, respectively. The snails depurated 89% of the retained residues, of which the majority remained unchanged PNP (96.1%); metabolites were identified to be p-nitrophenyl sulfate (1.7%), p-acetomidophenol (1.4%), p-nitroanisole (0.5%), and p-aminophenol (0.3%).