Induction of aryl hydrocarbon hydroxylase by chlorinated dibenzofurans in rats

Five of 25 chlorinated dibenzofurans induced aryl hydrocarbon hydroxylase in rats when administered orally at 40 μg/kg body weight. Active inducers included the three congeners with chlorines in all four lateral positions and the 2,7- and 2,8-dichlorodibenzofurans. The findings agree well with other studies involving common congeners, but do not agree with findings in that congeners with three lateral chlorines were inactive .