Reduction in rat oocyte fertilizability mediated by S-(1, 2-dichlorovinyl)-L-cysteine: a trichloroethylene metabolite produced by the glutathione conjugation pathway.

Trichloroethylene (TCE), a commonly used industrial degreasing solvent and environmental toxicant, reduces rat oocyte fertilizability by an incompletely understood mechanism. Previous evidence implicated cytochrome P450 dependent oxidation of TCE. The current study investigated a second pathway, glutathione conjugation using S-(1,2-dichlorovinyl)-L-cysteine (DCVC), a mutagenic and cytotoxic TCE-metabolite. In vitro exposure of oocytes and in vivo exposure of females to DCVC significantly reduced oocyte fertilizability (63% vs. 26%; p < 0.005 and 60% vs. 36%; p < 0.005, respectively). Reduced fertilizability of oocytes following in vivo TCE exposure may be mediated partially by the glutathione conjugation pathway.