Effects of deltamethrin and its commercial formulation DECIS on different cell types in vitro: Cytotoxicity,cellular binding,and intracellular localization

To investigate the effect of deltamethrin and other pyrethroids on nonexcitable cells, we tested these molecules on animal (fibroblasts) and plant (algae) cells in culture. The effects of pyrethroids on cellular proliferation vary according to their structure. Deltamethrin (from 5 × 10⁻⁵ M) affected the growth of fibroblasts, but was inactive on other cells. Commercial formulations (DECIS EC and DECIS FLO) were more active to cells, but this effect was due mostly to the matrix. However, these matrices facilitated the penetration of deltamethrin into cells. Studies of ³H]deltamethrin uptake indicated the labeling of macromolecules, but labeling was reduced significantly after treatment with organic solvents. Autoradiographic studies with ³H]deltamethrin showed labeling of cells at the cytpolasmic level.