[Damage to the liver DNA of rats during the endogenous synthesis of N-nitrosodimethylamine].

The damage of liver DNA formation during endogenic synthesis of N-nitrosodimethylamine (NDMA) have been studied after introduction of its precursors, dimethylamine, amidopyrine and sodium nitrite, into the rat stomach. A combined administration of various doses of dimethylamine and nitrite increased the amount of single-strand DNA from 3.0 to 11.3%. The maximum DNA damage after administration of the precursors was observed after 24 h, and after 48 h it decreased to the control level. Pretreatment of rats with dimethylamine or nitrite increased the DNA damage induced by NDMA formation (37.4% and 41.6%, respectively).