[Free-radical processes under different conditions of body oxygen allowance]

Free radical processes (FRP) in mammalian organism are oxygen-depended. The review is devoted to the analysis of pro- and antioxidant processes in mammalian tissues under different oxygen supply conditions. There are described: sources of free radicals; hyperproduction of FRP under hyperoxia and hyperbaria; the role of free radicals in the adaptation to chronic hypoxia (high altitudes, barochamber, chronic heart and lung diseases); production of active oxygen species during the reoxygenation of preliminarily hypoxic tissues; FRP under intermittent hypoxic training; role of FRP in the chemoreception of oxygen. The special attention is paid to three main factors underlined the FR production in hypoxic conditions: the speed of hypoxia increase, the degree of hypoxia and the time of hypoxic exposure.