Increased incidence of hepatic foci and nodules in rats given one or two doses of 1,2-dibromoethane.
Livers of male Sprague-Dawley rats were evaluated for foci and nodules 90 days and 16 months after one or two oral doses of 1,2-dibromoethane (DBE). Rats (190 g) were given the following oral treatments. Controls received corn oil (2.5 ml/kg) at 0 and 24 hr. DBE X 1 received corn oil at 0 hr and 75 mg DBE/kg at 24 hr. DBE X 2 received 75 mg DBE/kg at 0 and 24 hr. All rats underwent a two-thirds partial hepatectomy at 28-29 hr, a one-third partial hepatectomy at 90 days, and were given 0.05% phenobarbital in drinking water for 4 months beginning at 1 yr. DBE was given to the DBE X 2 group twice within 24 hr because the compound is a hepatocyte mitogen. At 90 days, no appreciable changes were evident in any group. At 16 months, the incidence of nodules in the DBE X 2 group (25 of 41) was double that of the DBE X 1 group (12 of 38) (p less than 0.01) and triple that of the control group (6 of 34) (p less than 0.0001). Both the DBE X 1 and the DBE X 2 groups had higher incidences of eosinophilic foci, and also higher numbers, larger sizes, and larger areas of gamma-glutamyltranspeptidase-positive foci than the control group. These results demonstrate for the first time that hepatocyte foci and nodules are initiated by limited exposure of animals to DBE.
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D015946:Ethylene Dibromide / Q000633:toxicity*; D006651:Histocytochemistry; D006842:Hydrocarbons, Brominated / Q000633:toxicity*; D008099:Liver / Q000187:drug effects / Q000473:pathology*; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced* / Q000473:pathology; D008297:Male; D008934:Mitogens; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D006842:Hydrocarbons, Brominated; D008934:Mitogens; D015946:Ethylene Dibromide