Metabolism and disposition of 1,4,7,8-tetrachlorodibenzo-p-dioxin in rats

Article abstract of DOI:10.1016/S0045-6535(98)00255-0

Metabolism studies of 1,4,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a relatively nontoxic dioxin congener, were undertaken to gain a better understanding of mammalian metabolism of dioxins without the problems associated with the use of the most toxic congener, 2,3,7,8-TCDD. ¹⁴C- 1,4,7,8-TCDD was dosed to conventional and bile-cannulated rats at a level of 8 mg/kg. The ¹⁴C was excreted almost entirely in 72 hours with the major routes of excretion feces and bile. Metabolites were identified from the feces, bile, and urine by GC-MS or negative ion FAB MS and ¹H NMR. The two major fetal metabolites were hydroxylated tetra- and triCDDs. Glucuronide and sulfate conjugates of these hydroxyl metabolites were found in the urine and bile. Minor metabolites included dichlorocatechol, dihydroxylated tetra- and triCDDs, and conjugates of these compounds.