Hepatotoxicity of dimethylnitrosamine in cats and lizards

The hepatotoxic effects of the oral administration of a single dose of 50 mg dimethylnitrosamine (DMN)/kg and daily doses of 5 mg and 1 mg/kg, respectively, to cats and lizards were studied by light microscopy. Centrilobular necrosis was the main alteration detected in the liver of cats as in other animal species studied. The lizards, however, appeared unaffected. Morphological changes observed in the liver of these reptiles included haemorrhage, vacuolation of hepatocytes and diffuse nuclear changes; including pyknosis, karyorrhexis and karyolysis. Haemorrhage was also evident in the liver of cats as well as leukocytic infiltration;. including macrophages, lymphocytes and neutrophils. Cats appeared to be more susceptible to DMN poisoning.