Review of the Environmental Protection Agency's Draft IRIS Assessment of Tetrachloroethylene (2010) / Chapter Skim
Currently Skimming:
2 Overview of the Toxicokinetics of Tetrachloroethylene
2 Overview of the Toxicokinetics of Tetrachloroethylene
Pages 24-29
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 24... ...
The draft IRIS assessment includes a thorough cataloging of the published literature on tetrachloroethylene metabolism, including consideration of the specific metabolite isoforms that may be involved and polymorphic variants. This chapter presents a brief overview of the absorption, distribution, metabolism, and excretion of tetrachloroethylene to provide context for discussions in this report.
|
From page 25... ...
Despite the low overall metabolism of tetrachloroethylene compared with other chlorinated solvents, its metabolism has been studied extensively in both human volunteers and laboratory animals, using both in vivo and in vitro techniques. The studies showed that many metabolites are produced, including some known to be cytotoxic, mutagenic or both.
|
From page 26... ...
. Mechanistic studies on the products of CYP oxidation of tetrachloroethylene indicate that trichloroacetyl chloride is the predominant product of the CYPtetrachloroethylene complex; formation of tetrachloroethylene epoxide is much less favored (Yoshioka et al.
|
From page 27... ...
TCVG induces unscheduled DNA synthesis in mammalian kidney cells, and this response is blocked by inhibiting -glutamyltranspeptidase or β-lyase; such inhibition indicates that the genotoxic metabolite arises by the β-lyase pathway (Vamvakas et al.
|
From page 28... ...
Plasma albumin adducted with the trichloro derivative, indicating metabolism by the CYP pathway, was found in rats and humans exposed to tetrachloroethylene at 40 ppm for 6 hours. Immunochemical staining was used; the staining of protein from rats was 15-20 times more intense than that of protein from humans (Pahler et al.
|
From page 29... ...
The β-Lyase Pathway Metabolism by the β-lyase pathway results in formation of dichloro protein adducts and DCA. Dichloro albumin adducts were detected in rat, but not human, blood samples after tetrachloroethylene exposure (Pahler et al.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.