[Role of free oxygen radicals in the pathogenesis of internal diseases]

In the organism a part of molecular oxygen is converted into highly reactive radicals (superoxid, hydroxyl radical), which react with biological structures (proteins, nucleic acids, membranes). It is one of the general mechanisms of tissue damage, which occurs e. g. in ischemic reoxygenation, i. e. following intestinal, myocardial infarction; further in the site of inflammation the macrophages release superoxid extracellularly; in acute pancreatitis; in oxygenotherapy and other pathologic conditions. In all tissues there exists a protective system which, under physiological conditions, inactivates the toxic radicals. Enzymes (superoxid dismutase, physiological conditions, inactivates the toxic radicals. Enzymes (superoxid system, alpha-tocopherol, ascorbic acid are part of this system. The concept of tissue damage by radicals enables a new view on etiopathogenesis of some diseases and leads to endeavour to use the acquired knowledge in human medicine.