Metabolic activation of selected aromatic amines and polycyclic hydrocarbons by isolated subcellular fractions of Drosophila melanogaster.

The applicability of microsomal preparations from Drosophila melanogaster as the metabolic factor in the Salmonella mutagenicity assay with strains TA98 and TA100 was evaluated. Isolated cellular fractions (S27) from PB-pretreated flies activated N-acetyl-2-aminofluorene (2-AAF), N-hydroxy-N-acetyl-2-aminofluorene (N-OH-AAF), benzo[a]pyrene (BP), 9,10-dimethylanthracene (DA) and 2-naphthylamine (NA) into mutagenic metabolites. 7,-12-Dimethylbenz[a]anthracene (DMBA) was ineffective under the conditions of the test. This study was performed in an effort to determine optimal conditions for activating, by Drosophila enzymes, aromatic amines and polycyclic hydrocarbons, with 2-AAF and BP as model mutagens. The following alterations improved the sensitivity of this combined Salmonella/Drosophila assay. (1) Incubation of the plates at 25 degrees C for 1 night instead of permanent exposure at 37 degrees C. (2) Isolation of S27 fractions instead of the conventional S9, because 9000 X g was not sufficient to spin down Drosophila mitochondria.