Effect of an essential fatty acid deficient diet on dimethylnitrosamine demethylation and derangement of liver polyribosomes induced by this drug.

Cytochrome P-450 content and dimethylnitrosamine demethylase activity were determined in the liver of male rats fed a polyunsaturated fatty acid deficient diet. The damaging activity of dimethylnitrosamine (DMN) on liver polyribosomes of control and treated rats was estimated. The reduction of DMN demethylase activity did not protect against polysome derangement due to DMN. These data are consistent with the hypothesis that metabolic pathways, other than the P-450 dependent one, are involved in the DMN bioactivation.