Respiratory burst

The oxidative burst ( burst Sheet for " onset ," " burst " or " burst " ), also referred to as respiratory burst, is the release of reactive oxygen species ( " oxygen free radicals " ) by neutrophils and macrophages in the phagocytosis.

Discovery and description of the oxidative burst

1933 discovered Baldridge and Gerhard that in phagocytosis of the oxygen consumption of the granulocytes in the 50 - to 100-fold increases value. Connected to the oxygen consumption is the gradual development of various reactive oxygen species. The process is catalyzed by the enzyme NADPH oxidase. By a stimulus of granulocyte activation, and the reaction is initiated is done. Under the mediation of the NADPH oxidase of oxygen and nicotinamide adenine dinucleotide phosphate ( NADPH), the hyperoxide anion O2 - generated. The highly reactive hyperoxide itself is the starting product for the synthesis of a number of other reactive oxygen species. For example, produced by a reaction catalyzed by superoxide dismutase significantly more stable the disproportionation of hydrogen peroxide. The hydrogen peroxide can very easily penetrate as a neutral, water- like molecule in cells. In the catalytic decomposition of hydrogen peroxide, the highly reactive hydroxyl radical · OH, that can attack a variety of molecules is formed.

Of hydrogen peroxide and the simultaneous presence of oxygen radicals can be formed by myeloperoxidase from the primary granules of chloride ions, the oxidant hypochlorous acid ( HClO ).

Importance

These reactive oxygen species, it is the neutrophils and macrophages possible intracellular digestion of phagocytosed ( " eaten "), foreign bodies, such as, for example, to accomplish pathogens. These oxidizing agents react with other proteins, nucleic acids and other cellular components of the pathogens. They also deactivate endogenous protease inhibitors that would prevent the breakdown of proteins.

The importance of the oxidative burst for the defense is illustrated by the clinical picture of septic granulomatosis and Myeloperoxidasedefekt.