1,2-Dibromoethane causes rat hepatic DNA damage at low doses

Two oral doses of 1,2-dibromoethane (10-300 mumol/kg) were given to adult female rats 21 and 4 hours before sacrifice. Then hepatic DNA damage, ornithine decarboxylase, cytochrome P-450 content, glutathione content and serum alanine aminotransferase activity assays were performed. In addition, DNA damage was assessed in blood, bone marrow, kidney, spleen and thymus. Of the six organs studied, liver showed the largest amount of DNA damage. Doses at or above 10 mumol/kg EDB caused DNA damage as determined by the alkaline elution technique. Far greater doses (300 mumol/kg, 56.4 mg/kg) of EDB were required to cause other biochemical effects, such as increased activity of ornithine decarboxylase. Thus, the carcinogen EDB caused substantial DNA damage at doses far below those required to show other biochemical effects or frank liver toxicity. DNA damage occurred at a dose level 40-fold lower than that demonstrated in previous studies.