METABOLISM AND MUTAGENIC ACTIVATION OF BENZO(A)PYRENE BY SUBCELLULAR-FRACTIONS FROM MUSSEL (MYTILUS-GALLOPROVINCIALIS) DIGESTIVE GLAND AND SEA BASS (DISCENTHRARCUS-LABRAX) LIVER

1. The formation of B(a)P diols, phenols and bacterial mutagens by mussel subcellular fractions is dependent on NADPH whereas B(a)P quinones, the major metabolites, appear to be produced by radical reactions and chiefly in the absence of NADPH. 2. B(a)P metabolism in sea bass liver fractions is totally dependent on NADPH and insensitive to radical scavengers excepted tocopherol inhibition of B(a)P mutagenesis. 3. The 9-10 and 7-8 epoxides formed by sea bass microsomes have a high affinity for EH which readily metabolized all those epoxides to diols. 4. Alpha-naphtoflavone inhibits sea bass B(a)P metabolism at high concentration (100 muM) whereas it increases it at low concentration (20 muM).