[Free radicals in the central nervous system].
Central nervous system has a low antioxidative capacity, which is formed mainly by ascorbic acid. Therefore the cerebral tissue is threatened by the increased formation of free radicals and their metabolites (ROS--reactive oxygen species). ROS are formed such as in reperfusion phase after ischemia and in catecholamine metabolism, in oxidative stress due to hyperglycaemia. Polyunsaturated fatty acids (PUFA) are peroxidased by ROS; proteins and DNK are damaged as well. Free radicals are involved in etiology and pathogenesis of many CNS diseases, such as neuritis, Alzheimer disease, Parkinson disease, Huntington disease, aging and atherosclerosis of the brain, epilepsy, etc. During the antioxidant therapy it is necessary to consider the types of ROS, their origin and their mode of action, whether to administer hydrophilic or lipophilic antioxidants, eventually chelate agents, etc. Hydrophylic antioxidants are acting very soon after the administration, whereas the lipophilic ones reach their target tissues with a great delay. Therefore it is better to apply them preferentially like a prevention, if possible. Enzymatic antioxidants (SOD, GSPHx and catalase and others) are usually acting only for a short time. The methods of estimation of free radicals attacks are discussed as well their possible pathophysiological effects.
Rokyta
R
R
Ustav fyziologie a klinické fyziologie 3. lékarské fakulty UK, Praha.
Racek
J
J
Holecek
V
V
D000818:Animals; D002490:Central Nervous System / Q000378:metabolism*; D002493:Central Nervous System Diseases / Q000378:metabolism; D005609:Free Radicals / Q000378:metabolism*; D006801:Humans; D017382:Reactive Oxygen Species / Q000378:metabolism
D005609:Free Radicals; D017382:Reactive Oxygen Species
Volné radikály v centrálním nervovém systému.