The inducible nitric oxide synthesis (iNos) is a macrophage mechanism to produce free radicals. This enzyme is absent in the cytosol of quiescent macrophages but its synthesis can be rapidly induced for the combined action of LPS and INF-gamma. INos catalyzes the conversion of arginine into citrulline, resulting in the release of diffusible nitric oxide, which at acid level can be combined with hydrogen peroxide or superoxide generated by the oxidase system by generating highly peroxinitric radicals reactive bacteria, which kill microbes with very high efficiency.
wiki
