Fate of oxygen free radicals in extracellular fluids.

1. Oxygen radicals in biological systems and the importance of iron Oxygen radicals can be either organic or inorganic. The organic radicals such as the peroxy (ROO') and alkoxy (RO') are those derived from complex molecules like the polyunsaturated fatty acids. The inorganic oxygen radicals are the superoxide radical (O,-*) and the hydroxyl radical (OH'). Formation of the highly reactive hydroxyl radical appears to be due to either ionizing radiation or to the simultaneous presence of superoxide and hydrogen peroxide with suitable iron catalysis, i.e. 20,-' + 2H+ + H,O, + 0,