Hepatic Tumors in the Guppy (Lebistes reticulatus) Induced by Aflatoxin B1, Dimethylnitrosamine, and 2-Acetylaminofluorene2

Abstract

Guppies (Lebistes reticulatus) were fed 0.6 mg aflatoxin B₁, 480 mg dimethylnitrosamine, or 30 mg 2-acetylaminofluorene/100 g powdered diet for several months. These carcinogens induced hepatic damage, hyperplastic nodules, and tumors of the liver, together with damage and tumorous lesions of other organs. Among fish receiving aflatoxin B₁, 2 of 5 had hepatic tumors after 9 months and 7 of 11 after 11 months. Hepatic tumors were found after 13 months in 2 of 20 fish given dimethylnitrosamine. The latter also had granulomatous kidney lesions and leiomyosarcoma in the mesentery. With 2-acetylaminofluorene, 1 of 3 fish developed hepatic tumors after 11 months and 3 of 13 fish after 13 months. Carcinogenesis in a small fish such as the guppy provides a suitable model for simplifying carcinogenic experiments, and the possibility of use of these fish to screen environmental carcinogens is discussed.