Toxicokinetics

 

作者: Angelique P. J. M. Van Birgelen,   Martin Vann De Berg,  

 

期刊: Food Additives & Contaminants  (Taylor Available online 2000)
卷期: Volume 17, issue 4  

页码: 267-273

 

ISSN:0265-203X

 

年代: 2000

 

DOI:10.1080/026520300283342

 

出版商: Taylor & Francis Group

 

关键词: Body Burden Lipophilicity Metabolism Receptor Binding Species Difference

 

数据来源: Taylor

 

摘要:

The toxicokinetic determinants of dioxin and related chemicals depend on three major properties: lipophilicity, metabolism, and binding to CYP1A2 in the liver. The induction of CYP1A2 is partially under the control of the aryl hydrocarbon receptor (AhR). Lipophilicity increases with more chlorination and controls absorption and tissue partitioning. Metabolism is the rate limiting step for elimination. Induction of CYP1A2 leads to hepatic sequestration of TCDD. Binding to this inducible hepatic protein results in non-linear dosedependent tissue distribution: with increasing doses, the relative concentration in extra-hepatic tissues decreases while that in liver increases. The induction of this protein occurs in both animals and humans and results in an increase in the liver to fat ratio of these compounds. Humans have similar sensitivities to rodents for dioxin-like compounds when using tissue concentration (from in vitro studies), body burden, average lifetime serum lipid concentration, or lifetime area-under-the-curve concentration based on both low dose (biochemical) and high dose (cancer) driven endpoints. To reach the same tissue concentration in humans as rodents however, humans need a lower daily intake than rodents based on differences in pharmacokinetic behaviour. This clearly indicates that physiologically based pharmacokinetic models should be explored for the estimation of the daily intake of dioxin-like compounds in humans based on tissue dose levels or derivatives of those.

 

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