ISSN:
1573-4919
Keywords:
mitochondria (rat liver)
;
lipid peroxidation
;
antioxidants
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract Mitochondria are cellular organelles where the generation of reactive oxygen species may be high. They are, however, effectively protected by their high capacities of antioxidative systems, as enzymes and either water or lipid soluble low molecular weight antioxidants. These antioxidative defence systems can be effectively regenerated after or during an oxidative stress as long as the mitochondria are in an energized state. Energization of mitochondria mainly depends on the availability of suitable respiratory substrates which can provide hydrogen for the reduction of either the glutathione- or α-tocopherol-system, since GSH is regenerated by glutathione reductase with the substrate NADPH and the α-tocopheroxyl-radical likely by reduced coenzyme Q. It was shown that mitochondria do not undergo damages as long as they can keep a high energy state. The delicate balance between prooxidative/antioxidative activities can be shifted towards oxidation, if experimentally prooxidants were added. After exhaustion of the antioxidative defence systems damages of rnitochondrial functions become expressed followed by membrane injuries along with the oxidation and degradation of mitochondrial lipids and proteins leading finally to the total degradation of the mitoc hondria. Extramitochondrial antioxidants may assist the mitochondrial antioxidative defence systems in a complex way, whereby particularly ascorbic acid can act both as prooxidant and as antioxidant. (Mol Cell Biochem 174: 199–205, 1997)
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1006804423627
Permalink
