[Effect of HF on the hepatic metabolism of dimethylnitrosamine in the rat].

The authors have studied the action of fluorine, administered by inhalation, on the liver metabolism of a chemical carcinogen: dimethylnitrosamine (DMN). The results demonstrate a decrease in the level of cytochrome P450 and in the activity of benzo(a)pyrene hydroxylase in animals treated with DMN or DMN + HF. The greater inhibition in the presence of HF is paralleled by a decrease in the weight of the liver and in the synthesis of liver microsomal proteins. This reduction of activity (with the exception of dimethylnitrosamine demethylase which is unaffected) is supported by the result of the histological examinations showing two different types of lesion-necrotic toxic hepatitis and post-hepatitic cirrhosis - the frequency of which is much higher in the presence of fluorine.