EFFECTS OF PYRETHROID INSECTICIDES ON GAP JUNCTIONAL INTERCELLULAR COMMUNICATIONS IN BALB C3T3 CELLS BY DYE-TRANSFER ASSAY/

The effects of fenvalerate, esfenvalerate, permethrin, cypermethrin, d eltamethrin, p-chlorophenylisovaleric acid (CPIA, major metabolite of fenvalerare) and DDT, a liver tumor promoter, on gap junctional interc ellular communication (GJIC) were examined in Balb/c3T3 cells by dye-t ransfer assay. Separate groups of Balb/c3T3 cells were exposed to the chemicals for 1 day. On the following day, GJIC was measured by counti ng the number of dye-transferring cells per injection of Lucifer Yello w under a fluorescent microscope. Fenvalerate, esfenvalerate, permethr in, cypermethrin, deltamethrin and DDT inhibited GJIC at noncytotoxic concentrations, while CPIA did not inhibit GJIC even ar a cytotoxic co ncentration. It is concluded that the examined pyrethroid insecticides , but not a metabolite, have inhibitory effects on GJIC in Balb/c3T3 c ells.