THE EFFECT OF THE CYTOCHROME-P-450 SYSTEM INDUCERS ON THE DEVELOPMENTOF DROSOPHILA-MELANOGASTER

D. melanogaster development was markedly retarded and its survival dec reased by larvae treatment with compounds being strong inducers of the cytochrome P-450 2B in mammals-phenobarbital (PB), perfluorodecaline (PFD), trans-stilbene oxide (TSO), and triphenyldioxane (TPD). At the same time, the weak inducer hexobarbital or the selective cytochrome P-450 inducer in mice but not in rats 1,4-bis[2-(dichloropyridyl-oxy)] -benzene (DPB) did not affect the larvae development. The cytochrome P -450 1A1 inducers benzo(a)anthracene (BA) and beta-naphtoflavone (BNF) were also not effective. The toxicity of phenobarbital was shown to b e decreased by the cytochrome P-450 inhibitor piperonyl butoxide by ad ding 20-hydroxyecdysone or by treatment with aminophylline-the indirec t enhancer of ecdysone production in the larval prothoracic gland. The hypothesis of the moulting hormone degradation as the cause of elevat ed larvae mortality resulting from the induced high mixed function oxi dase activity has been discussed.