Microsomal enzyme induction by permethrin in rats

ABSTRAeT. The synthetie pyrethroid, permetnrin, was evaluated fo~ i:s aoil 1t) to a'ter heo8tic microsoma' drug-metaboiizing Tunction. roe influence of permethrir (2.5:75 cis-:-ans) on DJasma an:ipyrine Klne:IC~ ane v-glutamyltranspeptidase [y-GT?) activicv were 5tudie? in ~ats, After 3 oays of aominis:-alior Of 90 mg permethrin/kg/day, there was no significan: change in tne antipyrine nalf-j ife and the area unaer tne curve, whi ie th~ aopa~ent volume o; dlstribution and ciearanee were signif'cant!v nc~eased. Treatme,,: w th 190 mg permethrin/kg/day for 3 days decreased antipyrine naif-life and the area under the curvei ano Increased the apparen: volume o' distrioutlon and the clearance signiflcantlv. The y-GTD 8ctivity was significantly 1,cre8sed withln 2" aavs and 14 days after the start of permethri~ aaministrat10n at aoses of 90 and 190 ms permethrin/kg/day, resDectlve1y. The antlpyrlne kinetics resu'ts indicate that permethrin is caoablc of producing a dose-dependent marked enzyme-inducing effeet.