Dieldrin–Induced Mallory Bodies in Hepatic Tumors of Mice of Different Strains

Abstract

Mallory bodies (MBs) were induced in hepatic tumors by administration for up to 85 weeks of a diet containing 10 ppm dieldrin to 50 C3H/He and 62 C57BL/6J X C3H/He B6C3F1 male mice. MBs were seen in 15 of 28 (54%) mice which developed benign hepatic tumors and 33 of 45 (73%) mice with hepatocellular carcinoma, but in only 3 of 39 (8%) mice without hepatic tumors. In mice with tumors, the MBs were predominantly confined to tumor tissue and persisted in a carcinoma transplanted into a nude mouse. MBs were not observed, however, in hepatic tumors of 67 C57BL/ 6J, 49 C3H/He, or 81B6C3F1 mice given 12 jug diethylnitrosamine i.p. on Days 0, 3,9, and 15. Thirty–one of 195 control mice of all three strains had hepatic tumors. Only one of the controls had a tumor with an MB, and no MBs were seen in nontumor–bearing livers of control animals. These observations, coupled with the results of a previous study in which MBs were observed in hepatocytes of dieldrin–treated C57BL/6J mice, indicate that mice treated with dieldrin are a reliable animal model for the study of MBs.