FATE OF A TERMINAL OLEFIN WITH DROSOPHILA MICROSOMES AND ITS INHIBITORY EFFECTS ON SOME P-450 DEPENDENT ACTIVITIES

In vitro bioassays were used to analyze the metabolism of the 11-dodec enoic acid (11-DDNA) by microsomes prepared from Drosophila melanogast er RalDDT(R) strain. 11-DDNA is metabolized to 11,12-epoxylauric acid (epoxyLA) in a NADPH-dependent way. The microsomal production of epoxy LA reaches a plateau very quickly, suggesting the occurrence of an enz yme inactivation process. After incubation of microsomes with (1-C-14) 11-DDNA, three proteins of Mr approximate to 50 kDa were labeled. 11-D DNA inhibits the microsomal metabolism of lauric acid and 7-ethoxycoum arin in a time and NADPH-dependent process. An inhibition of metabolit es generated from DDT and testosterone was also obtained but at higher concentrations. These results are discussed according to the fact tha t RalDDT(R) is an insecticide resistant strain characterized as a high metabolizer of the insecticide DDT and also of lauric acid, testoster one, and ethoxycoumarin. (C) 1995 Wiley-Liss, Inc.