Metabolism of pentachloronitrobenzene by goats and sheep

The metabolic fate of a single oral dose of pentachloronitro( super(14)C)benzene (( super(14)C)PCNB) was examined in four goats and sheep. Two general pathways of metabolism were observed. One involved the reduction of the nitro group to an amine and formation of secondary metabolites such as the N-glucuronide of pentachloroaniline (PCA), the sulfamate of PCA, and tetrachloroaminophenol. This was the principal pathway for animals receiving 2 mg of ( super(14)C)PCNB/kg. Only ( super(14)C)PCA and small amounts of ( super(14)C)PCNB were identified in feces of these animals. The other pathway results in replacement of a nitro group with a sulfur-containing group such as a thiol, a methylthio, an N-acetylcysteine, and an S-glucuronide or in which both the nitro and a chlorine have been replaced to form compounds such as the S-glucuronide of tetrachloro(methylthio)thiophenol, bis(methylthio)tetrachlorobenzene) or S-((methylthio)tetrachlorophenyl)-N-acetylcysteine. This type of metatolism was observed with animals receiving 30 mg or more of ( super(14)C)PCNB/kg of body weight. In these animals, ( super(14))PCNB was isolated from feces in amounts equal to or greater than those of ( super(14)C)PCA.