THE ROLE OF NITROGEN-DIOXIDE IN ENDOGENOUS SYNTHESIS OF CARCINOGENIC NITROSAMINES

Carcinogenic N-nitrosamines (NA) have been proved to be formed endogen ously in white rats exposed to NO2 by inhalation. The incidence of tum ours, localization, malignancy, multiplicity, and detection time were found to be dependent on NO2 concentration. a number of facts includin g high occurrence of liver tumours, detection of N-nitrosodimethylamin e (NDMA) and N-nitrosodiethylamine (NDEA) in liver, lung, and kidney o f rats during administration of NO2 and other NA precursors demonstrat ed their danger with relation to potential NA endogenous synthesis and carcinogenic effect. At the same time, combined exposure to NO2 plus AP at the level of maximal permissible concentration (MPC) did not inf luence carcinogenesis in rat.