Promotion of hepatocarcinogenesis by hexachlorobenzene in energy-restricted rats

The interaction between dietary energy restriction and low dose of the fung icide hexachlorobenzene (HCB) was evaluated in a rat liver medium-term bioa ssay for carcinogenesis. Male Wistar rats were fed a control or a 50% energ y-restricted diet, both added or not with 50 ppm HCB, for 6 weeks. HCB expo sure or energy restriction separately did not exert any influence on the de velopment of glutathione S-transferase placental form (GST-P+) foci of hepa tocytes. Simultaneous HCB exposure and energy restriction induced a signifi cant increase in liver centrilobular hypertrophy and GST-P+ foci developmen t. Our findings suggest that energy restriction increases liver response to low dose of HCB, unmasking the promoting potential of this fungicide. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.