Reduction of the carcinogen 1-nitropyrene to 1-aminopyrene by rat intestinal bacteria.
The microbial metabolism of the mutagenic and carcinogenic polycyclic nitroaromatic hydrocarbon, 1-nitropyrene, has been studied. Under anaerobic conditions, bacterial suspensions from rat intestinal contents converted 1-nitropyrene to one major and two minor metabolites. The rate of metabolism by rat intestinal microflora (10(9) bacteria/ml) was rapid with greater than 90% conversion occurring within 1 h. The major metabolite was identified as 1-aminopyrene through high pressure liquid chromatographic and mass spectral comparisons with an authentic standard. The suspected metabolites, N-acetyl-1-aminopyrene, 1-nitrosopyrene, N-hydroxy-1-aminopyrene, and 3-, 6-, and 8-hydroxy-1-nitropyrene were synthesized, but these derivatives were not detected in culture extracts from rat intestinal contents incubated anaerobically with 1-nitropyrene. Nine genera of anaerobic and facultative bacteria normally associated with the intestine also converted 1-nitropyrene to 1-aminopyrene. These data indicate that a wide range of intestinal bacteria are able to reduce 1-nitropyrene. The results are discussed in relation to the in vivo metabolism of this polycyclic nitroaromatic hydrocarbon.
D000693:Anaerobiosis; D000818:Animals; D001419:Bacteria / Q000302:isolation & purification / Q000378:metabolism*; D001711:Biotransformation; D002273:Carcinogens; D007422:Intestines / Q000382:microbiology*; D009152:Mutagenicity Tests; D009153:Mutagens; D009154:Mutation; D011721:Pyrenes / Q000302:isolation & purification / Q000378:metabolism* / Q000633:toxicity*; D051381:Rats; D012486:Salmonella typhimurium / Q000187:drug effects; D013045:Species Specificity
D002273:Carcinogens; D009153:Mutagens; D011721:Pyrenes; C004482:1-aminopyrene; C032668:1-nitropyrene