Dioxin Conference
Skip to content

EHP

Advance Publication

Environ Health Perspect; DOI:10.1289/ehp.1307623

Physiologically Based Pharmacokinetic (PBPK) Modeling of Interstrain Variability in Trichloroethylene Metabolism in the Mouse

Weihsueh A. Chiu,1 Jerry L. Campbell Jr.,2 Harvey J. Clewell III,2 Yi-Hui Zhou,3 Fred A. Wright,3 Kathryn Z. Guyton,1 and Ivan Rusyn
Author Affiliations close
1National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC, USA; 2The Hamner Institutes for Health Sciences, Research Triangle Park Park, NC, USA; Departments of 3Biostatistics and 4Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC, USA
About This Article open

This EHP Advance Publication article has been peer-reviewed, revised, and accepted for publication. EHP Advance Publication articles are completely citable using the DOI number assigned to the article. This document will be replaced with the copyedited and formatted version as soon as it is available. Through the DOI number used in the citation, you will be able to access this document at each stage of the publication process.

Citation: Chiu WA, Campbell JL Jr., Clewell HJ III, Zhou YH, Wright FA, Guyton KZ, Rusyn I. Physiologically Based Pharmacokinetic (PBPK) Modeling of Interstrain Variability in Trichloroethylene Metabolism in the Mouse. Environ Health Perspect; http://dx.doi.org/10.1289/ehp.1307623.

Received: 10 September 2013
Accepted: 10 February 2014
Advance Publication: 11 February 2014

For materials with complex tables, EHP offers “Alt 508″ versions optimized for use with screen-reading software.

Accessible PDF icon PDF Version (2.8 MB) | Accessible PDF icon Supplemental Material 1 (3.9 MB) | Accessible PDF icon Supplemental Material 2 (270 KB)

Abstract

Background: Quantitative estimation of toxicokinetic variability in the human population is a persistent challenge in risk assessment of environmental chemicals. Traditionally, inter-individual differences in the population are accounted for by default assumptions or, in rare cases, are based on human toxicokinetic data.

Objectives: To evaluate the utility of genetically diverse mouse strains for estimating toxicokinetic population variability for risk assessment, using trichloroethylene (TCE) metabolism as a case study.

Methods: We used data on oxidative and glutathione conjugation metabolism of TCE in 16 inbred and one hybrid mouse strains to calibrate and extend existing physiologically-based pharmacokinetic (PBPK) models. We added one-compartment models for glutathione metabolites and a two-compartment model for dichloroacetic acid (DCA). A Bayesian population analysis of interstrain variability was used to quantify variability in TCE metabolism.

Results: Concentration-time profiles for TCE metabolism to oxidative and glutathione conjugation metabolites varied across strains. Median predictions for the metabolic flux through oxidation was less variable (5-fold range) than that through glutathione conjugation (10-fold range). For oxidative metabolites, median predictions of trichloroacetic acid production was less variable (2-fold range) than DCA production (5-fold range), although uncertainty bounds for DCA exceeded the predicted variability.

Conclusions: Population PBPK modeling of genetically diverse mouse strains can provide useful quantitative estimates of toxicokinetic population variability. When extrapolated to lower doses more relevant to environmental exposures, mouse population-derived variability estimates for TCE metabolism closely matched population variability estimates previously derived from human toxicokinetic studies with TCE, highlighting the utility of mouse interstrain metabolism studies for addressing toxicokinetic variability.


WP-Backgrounds Lite by InoPlugs Web Design and Juwelier Schönmann 1010 Wien