CYTOTOXIC EFFECTS AND INDUCTION OF CYTOCHROMES P450 1A1 2 BY INSECTICIDES, IN HEPATIC OR EPIDERMAL-CELLS - BINDING CAPABILITY TO THE AH RECEPTOR/

Insecticides deserve particular attention since the general population is potentially exposed to such chemicals through many routes. We ther efore tested the comparative acute and chronic toxicity of chemicals b elonging to the major insecticides families (DDT, malathion and tetrac hlorvinphos, carbaryl, cypermethrin, diflubenzuron), in hepatocytes, H epG2 and HaCaT cell lines. Two kinds of end-points were used: cytotoxi city parameters and CYP1A1 induction. Except for cypermethrin and difl ubenzuron, all these chemicals exerted a cytotoxic effect in hepatocyt es and HaCaT, but not in HepG2 cells. However, the induction of the ER OD activity appeared more sensitive since a response was detected at l ower concentrations. Significant differences were observed between the cell types and the insecticides. Furthermore, these chemicals were un able to displace [H-3]TCDD from its binding sites, suggesting that the y would not be a ligand of the Ah receptor. The experimental approach used herein may be a good means for predicting the acute and chronic t oxicity of pesticides. (C) 1998 Elsevier Science Ireland Ltd. All righ ts reserved.