Reactive oxygen species

Also referred to often inaccurate as " oxygen radicals" - - Reactive oxygen species (English reactive oxygen species, ROS) are harmful to the organism forms of oxygen, which play an important pathophysiological role in oxidative stress and thus in a wide variety of diseases as well as in aging. Reactive oxygen species cause proteins in protein oxidation and lipid peroxidation in lipids.

Among the ROS for a free radicals are like the superoxide anion (old name: superoxide anion) O2 · - the highly reactive hydroxyl radical OH ·, the peroxyl radical ROO · and the alkoxyl radical RO · of lipids, on the other stable molecular oxidants such as hydrogen peroxide H2O2, hydroperoxide ROOH, ozone O3 and the hypochlorite anion OCl -, and excited oxygen molecules ( singlet oxygen 1O2 ).

The ROS in an overview:

Reactive oxygen species in the organism in the mitochondria as a by- product of respiration occur ( by monoamine oxidases in the respiratory chain and of complex I and complex III ), but also by inflammatory cells to damage as viruses and bacteria. ROS (especially hydrogen peroxide and nitric oxide ) are also applied in plant defense against pathogens used.

Environmental toxins and cigarette smoke are more important sources of reactive oxygen species.

By the reaction of the superoxide anion O2 · - to nitrogen monoxide NO produced · ONOO peroxynitrite also, together with nitric oxide which is also referred to as reactive nitrogen species (RNS ) and a reactive compound is also high (although not a free radical ). ROS and RNS are thus important oxidants which counteract the antioxidants in the body.

Recent studies Write ROS such as superoxide and hydrogen peroxide in addition to generation of oxidative stress an important signaling function for example in the brain in signal transmission, synaptic plasticity and memory formation to. They work there also heavily vasodilator ( vasodilators ) and seem therefore important for the increase of cerebral blood flow and cerebrovascular tone to be. Furthermore, they influence on the Wnt signaling pathway growth and division of cells in the regeneration of severed tails of tadpoles and lizards.

The formation of reactive oxygen metabolites by the monoamine oxidases (MAO ) can be prevented by MAO inhibitors such as the anti- Parkinson drug selegiline or rasagiline. These drugs therefore be neuroprotective.

Swell

• Chemicals group
• Oxygen compound
• Biochemistry