Bioaccumulation of tetra-through octachlorinated dibenzo-p-dioxins in two different mixtures and their biochemical effects on enzymes of carbohydrate metabolism in mice

Two different mixtures of various PCDD homologues and congeners originating from octachlorodibenzo-p-dioxin by dechlorination were administered by oral gavage once a week to C57Bl/6 (B6) and DBA/2J (D2) mice, respectively, for up to 15 weeks followed by a short recovery period. Each mouse strain was tested with two different doses of these mixtures as well as with 2,3,7,8-TCDD. Neither the clinical symptoms nor the development of body weight varied from those observed in control animals. Liver weight increased in a dose-dependent manner, and significant treatment-specific thymus involution was observed. TCDD and most of the 2,3,7,8-congeners reached steady state concentrations in the liver approximately 10 weeks after starting the administration.Modulations in carbohydrate metabolism were observed in the liver under the influence of all treatments.