title: Evidence that epichlorohydrin is not a toxic metabolite of 1,2-dibromo-3-chloropropane.
abstract: The major urinary metabolite of 14C-epichlorohydrin, after oral administration to rats, was identified previously (Gingell et al. 1985) to be N-acetyl-S-(3-chloro-2-hydroxypropyl)-L-cysteine (ACPC) at 36% of the administered dose. In a similar study reported here, 1,2-dibromo-3-chloropropane (DBCP) was metabolized to at least 20 radioactive urinary metabolites. ACPC was only a minor metabolite (4%) of DBCP. Epichlorohydrin was metabolized in vitro by rat liver microsomes to alpha-chlorohydrin, but DBCP was not metabolized to epichlorohydrin or alpha-chlorohydrin under similar conditions. Covalent binding of radioactivity to liver microsomal proteins occurred for both substrates, but was less for 14C-epichlorohydrin than for 14C-DBCP. Addition of 3,3,3-trichloropropylene oxide, an inhibitor of epoxide hydrolase, increased the extent of protein binding of epichlorohydrin, but decreased the amount of 14C-DBCP which was bound. The data indicate the epichlorohydrin is not a significant in vivo nor in vitro metabolite of DBCP in the rat, and is unlikely to be responsible for the toxicity of DBCP.
mesh_terms: D000818:Animals; D001711:Biotransformation; D002728:Chlorohydrins / Q000378:metabolism*; D002849:Chromatography, Gas; D002855:Chromatography, Thin Layer; D004811:Epichlorohydrin / Q000378:metabolism*; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism; D011407:Propane / Q000031:analogs & derivatives* / Q000378:metabolism / Q000633:toxicity / Q000652:urine; D011506:Proteins / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D002728:Chlorohydrins; D011506:Proteins; D004811:Epichlorohydrin; C007318:1,2-dibromo-3-chloropropane; D011407:Propane