Effects of Simultaneous Dietary Exposure to 2,2′,4,4′,5,5′-Hexabromobiphenyl and 3,3′,4,4′,5,5′-Hexachlorobiphenyl on Hepatic Tumor Promotion in Rats

Publisher Website
Google Scholar
Abstract
Female Sprague-Dawley rats were partially hepatectomized, initiated with diethylnitrosamine (DEN), and fed diets containing 2,2′,4,4′,5,5′-hexabromobiphenyl (245-HBB), 3,3′,4,4′,5,5′-hexachlorobiphenyl (345-HCB), or combinations of 245-HBB and 345-HCB to determine the tumor-promoting ability of these compounds in a two-stage (initiation/promotion) hepatocar-cinogenesis system. Tumor-promoting ability was assessed by measuring hepatic foci positive for gamma glutamyl transpeptidase (GGT) activity. Concentrations of 10 or 100 mg 245-HBB/kg of diet caused significantly increased numbers of GGT-positive hepatic foci. When 245-HBB and 345-HCB were fed simultaneously, an additive effect on tumor-promoting ability was observed at dietary concentrations of 10 mg/kg 245-HBB and 0.1 mg/kg 345-HCB. However, an inhibitory effect on tumor promotion occurred when dietary concentrations of 100 mg/kg 245-HBB and 1.0 mg/kg 345-HCB were fed simultaneously. These results suggest that the tumor-promoting ability of simultaneous exposure to 245-HBB and 345-HCB can be additive or inhibitory depending upon the concentration of each congener in the diet.

This publication has 17 references indexed in Scilit: