Activation of benzo[a]pyrene and 2-aminoanthracene to bacteria mutagens by mussel digestive gland postmitochondrial fraction.
The ability of the mussel postmitochondrial fraction (S9) to activate benzo[a]pyrene (BaP) and 2-aminoanthracene (2AA) to mutagenic metabolites towards Salmonella typhimurium strain TA98 was tested. The mechanisms involved in this activation were investigated and mussel cytochrome P-450-dependent monooxygenases and its NADPH cytochrome c reductase were found to contribute to the activation of BaP. This activation was improved by treating the mussel with 4,5,4',5'-tetrachlorobiphenyl (TCB) (a 3-methylcholanthrene-type inducer of cytochrome P-450-dependent monooxygenase in marine fish) and was inhibited by alpha-naphthoflavone (ANF), a cytochrome P-450 inhibitor. However, both BaP activation and cytochrome P-450-related metabolic activities are much weaker in mussels than in vertebrates. Mussel S9 activates aromatic amines more effectively than BaP. Pretreatment of mussels with TCB or addition of ANF in the incubation medium has no effect on 2AA activation. As suggested by Kurelec (1985), aromatic amine metabolism may be supported by a flavoprotein mixed-function amine oxidase which is NADPH-dependent.
Michel
X R
XR
Laboratoire de Toxicologie Alimentaire, Université de Bordeaux I, Talence, France.
Cassand
P M
PM
Narbonne
J F
JF
D000818:Animals; D000873:Anthracenes / Q000378:metabolism / Q000633:toxicity*; D001564:Benzo(a)pyrene / Q000378:metabolism / Q000633:toxicity*; D001571:Benzoflavones / Q000378:metabolism; D001711:Biotransformation; D049872:Bivalvia / Q000201:enzymology; D002104:Cadmium / Q000494:pharmacology; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D004790:Enzyme Induction; D008110:Liver Extracts / Q000378:metabolism; D006899:Mixed Function Oxygenases / Q000378:metabolism; D009152:Mutagenicity Tests; D009153:Mutagens / Q000633:toxicity*; D009251:NADPH-Ferrihemoprotein Reductase / Q000378:metabolism; D011078:Polychlorinated Biphenyls / Q000378:metabolism; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics
D000873:Anthracenes; D001571:Benzoflavones; D008110:Liver Extracts; D009153:Mutagens; D002104:Cadmium; D001564:Benzo(a)pyrene; C011512:alpha-naphthoflavone; C006593:2-anthramine; D003577:Cytochrome P-450 Enzyme System; D011078:Polychlorinated Biphenyls; D006899:Mixed Function Oxygenases; D009251:NADPH-Ferrihemoprotein Reductase