Topical permethrin exposure inhibits antibody production and macrophage function in C57B1/6N mice

Permethrin was applied to the shaved dorsal interscapular region of C57Bl/6 N mice at doses of 0.5, 1.5 or 5.0 mul/day. These doses corresponded to app roximately 22-220 mg/kg/day topical insecticide. Mice were exposed to perme thrin in this manner daily for 10 or 30 consecutive days, or every other da y for 7 or 14 exposures. The splenic macrophage chemiluminescent response w as depressed in a dose-dependent manner at 2 and 10 days post-exposure to p ermethrin. Phagocytic ability of macrophages was not inhibited. Antibody pr oduction as shown by plaque-forming cell (PFC) assay decreased significantl y after 10 consecutive days of exposure to permethrin, These data indicate that topical permethrin exposure may produce systemic immune effects. (C) 2 001 Elsevier Science Ltd. All rights reserved.