The mechanisms of action of the carcinogenic nitroso and related compounds.

It is suggested that the proximate carcinogenic forms of dialkylnitrosamines are their oxidation products, which retain the alkylnitrosamino moiety, but have acquired a carbonyl function as a result of omega or beta oxidation of an alkyl group. Such metabolites resemble the locally acting carcinogenic "nitrosamides" and probably have become multifunctional. Their functional groups, being in close proximity, could ensure binding in a concerted manner with apposite reactive centres of chromatin to form a firm bridge, for example, between an amino group of nucleic acid base and thiols of protein chains.