USE OF IRON CHELATORS IN PREVENTING HYDROXYL RADICAL DAMAGE - ADULT-RESPIRATORY-DISTRESS-SYNDROME AS AN EXPERIMENTAL-MODEL FOR THE PATHOPHYSIOLOGY AND TREATMENT OF OXYGEN-RADICAL-MEDIATED TISSUE-DAMAGE

Tissue damage in many diseases is caused by hydroxyl radicals, generat ed during single electron reduction of oxygen. The first step is usual ly the formation of the superoxide radical. This radical is constantly formed in all living cells, and in particular during activation of ph agocytes or during reoxygenation following ischaemia. Damage, however, only occurs in the presence of catalytic transition metals of which i ron is the most important in human pathology. Oxygen-radical-mediated damage can be prevented by iron chelators, as has been demonstrated in numerous in vitro and in vivo experiments. A description is given as to how toxic oxygen products are formed in biological systems, and how organisms succeed in preventing autodestruction by scavenger molecule s. The use of iron chelators to prevent oxygen radical damage is revie wed with emphasis on possible clinical applications. The adult respira tory distress syndrome is described in more detail as a model for oxyg en-radical-mediated damage that can be successfully prevented with iro n chelators.