[Molecular aspects of toxic effects of nitric oxide].

Although Nitric oxide (NO) is involved in many physiological processes of the body, its physico-chemical properties may, under some conditions, become dangerous to living cells. NO exposure may be of endogenous (e.g. local overproduction by activated inflammatory cells) or exogenous origin (mainly by inhalation route). Together with a short review of potential sources of NO exposure, the author presents some molecular aspects of its toxic effects: prooxidant effect, genotoxicity and mutagenicity, impact on the cell cycle and feedback inhibitory effect on NO synthase.