Oxygen species, reactive

Toxic forms of oxygen, which are released during oxidative stress and thus during various types of stress. diseases (e.g. Wegener's granulomatosis) play a pathophysiological role. Furthermore, they play an important role in the aging process of the organism. ROS cause protein oxidation in proteins and lipid peroxidation in lipids:

• the hyperoxide anion (old name: superoxide anion) O2-
• the highly reactive hydroxyl radical OH-,
• the peroxyl radical ROO-
• the alkoxyl radical RO- of lipids.

Furthermore, stable molecular oxidants like:

• hydrogen peroxide H2O2
• Hydroperoxide ROOH
• Ozone O3
• Hypochlorite anion OCl-
• singlet oxygen 1 O2)

In an organism, reactive oxygen species are formed in the mitochondria. They accumulate as a "by-product" of cellular respiration. Reactive oxygen species are formed during phagocytosis by granulocytes and macrophages to damage viruses and bacteria. Environmental toxins and also cigarette smoke are further sources of ROS. The formation of ROS by the monoaminooxidases (MAO) can be prevented by MAO-inhibitors such as the antiparkinsonian drugs "Selegilin" or "Rasagilin". These drugs have a "neuroprotective" effect.