DEVELOPMENT OF ALTERNATIVE, EXOGENOUS METABOLISM SYSTEMS FOR

THE IDENTIFICATION OF MUTAGENIC COMPOUNDS IS AN IMPORTANT SOCIETAL GOAL. SHORT-TERM TESTS THAT EMPLOY MAMMALIAN ENZYMES (GENERALLY MIXED-FUNCTION OXIDASES FROM RAT LIVER) TO PROVIDE METABOLIC ACTIVATION OF PREMUTAGENS TO ULTIMATE MUTAGENS HAVE BEEN DEVELOPED FOR THIS PURPOSE. IT IS NOW CLEAR THAT SOME COMPOUNDS ARE ACTIVATED BY OTHER OXIDIZING ENZYMES, SUCH AS PEROXIDASES, THAT ARE NOT PRESENT IN RAT LIVER S-9 PREPARATIONS. THE USE OF PEROXIDASES IN ROUTINE MUTAGENICITY SCREENING HAS BEEN LIMITED BY THE COMMERCIAL UNAVAILABILITY OF MAMMALIAN PEROXIDASES. WE PROPOSE TO DEVELOP AND COMMERCIALIZE A SHORT-TERM MUTAGENICITY ASSAY THAT EMPLOYS A MAMMALIAN PEROXIDASE TO PROVIDE METABOLIC ACTIVATION AND L5178Y MOUSE LYMPHOMA CELLS TO DETECT MUTAGENS. IN PHASE I, WE WILL DETERMINE THE CONDITIONS UNDER WHICH A SERIES OF AROMATIC AMINES ARE OXIDIZED TO THE SAME EXTENT BY HIGHLY PURIFIED PROSTAGLANDIN H SYNTHASE. THESE CONDITIONS WILL BE USED TO SCREEN THE SAME SERIES OF AROMATIC AMINES FOR MUTAGENICITY IN PHASE II. IN ADDITION TO THE DETERMINATION OF CONDITIONS TO BE USED IN MUTAGENESIS ASSAYS, THE PHASE I RESEARCH WILL PROVIDE VALUABLE DATA ON THE EXTENT OF METABOLISM