Skip Navigation


ToxSci Advance Access originally published online on December 2, 2003
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
77/2/219    most recent
kfh032v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (7)
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Nichols, J. W.
Right arrow Articles by Whiteman, F. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Nichols, J. W.
Right arrow Articles by Whiteman, F. W.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Toxicological Sciences 77, 219-229 (2004)
Copyright © 2004 by the Society of Toxicology

BIOTRANFORMATION AND TOXICOKINETICS

A Physiologically Based Toxicokinetic Model for Dietary Uptake of Hydrophobic Organic Compounds by Fish

II. Simulation of Chronic Exposure Scenarios

John W. Nichols*,1, Patrick N. Fitzsimmons* and Frank W. Whiteman*

* Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Duluth, Minnesota, 55804

ABSTRACT

A physiologically based toxicokinetic (PBTK) model for dietary uptake of hydrophobic organic compounds by fish was used to simulate dosing scenarios commonly encountered in experimental and field studies. Simulations were initially generated for the model compound [UL-14C] 2,2',5,5'-tetrachlorobiphenyl ([14C] PCB 52). Steady-state exposures were simulated by calculating chemical concentrations in tissues of the predator corresponding to an equilibrium distribution between the fish and water (termed the bioconcentration or BCF residue data set). This residue data set was then varied in a proportional manner until whole-body chemical concentrations exhibited no net change for each set of exposure conditions. For [14C] PCB 52, the proportional increase in BCF residues (termed the biomagnification factor or BMF) required to achieve steady state in a food-only exposure was 2.24, while in a combined food and water exposure the BMF was 3.11. Additional simulations for the food and water exposure scenario were obtained for a set of hypothetical organic compounds with increasing log KOW values. Using gut permeability coefficients determined for [14C] PCB 52, predicted BMFs increased with chemical log KOW, achieving levels much higher than those reported in field sampling efforts. BMFs comparable to measured values were obtained by reducing permeability coefficients within each gut segment in a log KOW–dependent manner. This predicted decrease in chemical permeability is consistent with earlier work, suggesting that dietary absorption of hydrophobic compounds by fish is controlled in part by factors that vary with chemical log KOW. Relatively low rates of metabolism or growth were shown to have a substantial impact on steady-state biomagnification of chemical residues.

Key Words: physiologically based model; fish; dietary uptake.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Toxicol SciHome page
J. W. Nichols, P. N. Fitzsimmons, F. W. Whiteman, T. D. Dawson, L. Babeu, and J. Juenemann
A Physiologically Based Toxicokinetic Model for Dietary Uptake of Hydrophobic Organic Compounds by Fish: I. Feeding Studies with 2,2',5,5'-Tetrachlorobiphenyl
Toxicol. Sci., February 1, 2004; 77(2): 206 - 218.
[Abstract] [Full Text] [PDF]


Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.