Erythrocytes catalase

Intracellular H2O2 is catalytically removed by catalase. The enzyme contains Fe(III) at its active site and is found in the cytosol of erythrocytes as well as the mitochondria and peroxisomes of most other cells. The concentration of catalase in rheumatoid synovial fluid is extremely low and may only be present as a result of erythrocyte lysis. 

Higuchi, M., Cartier, L.J., Chen, M. and HoUoszy, J.O. (1985). Superoxide dismutase and catalase in skeletal muscle adaptive response to exercise. J. Gerontol. 40, 281-286. Hunter, M.I.S., Brzeski, M.S. and de Vane, P.J. (1981). Superoxide dismutase, glutathione peroxidase and thiobarbi-turic acid-reactive compounds in erythrocytes in Duchenne muscular dystrophy. Clin. Chim. Acta 115, 93-98. 

In 1977, Kellogg and Fridovich [28] showed that superoxide produced by the XO-acetaldehyde system initiated the oxidation of liposomes and hemolysis of erythrocytes. Lipid peroxidation was inhibited by SOD and catalase but not the hydroxyl radical scavenger mannitol. Gutteridge et al. [29] showed that the superoxide-generating system (aldehyde-XO) oxidized lipid micelles and decomposed deoxyribose. Superoxide and iron ions are apparently involved in the NADPH-dependent lipid peroxidation in human placental mitochondria [30], Ohyashiki and Nunomura [31] have found that the ferric ion-dependent lipid peroxidation of phospholipid liposomes was enhanced under acidic conditions (from pH 7.4 to 5.5). This reaction was inhibited by SOD, catalase, and hydroxyl radical scavengers. Ohyashiki and Nunomura suggested that superoxide, hydrogen peroxide, and hydroxyl radicals participate in the initiation of liposome oxidation. It has also been shown [32] that SOD inhibited the chain oxidation of methyl linoleate (but not methyl oleate) in phosphate buffer. 

Overproduction of free radicals by erythrocytes and leukocytes and iron overload result in a sharp increase in free radical damage in T1 patients. Thus, Livrea et al. [385] found a twofold increase in the levels of conjugated dienes, MDA, and protein carbonyls with respect to control in serum from 42 (3-thalassemic patients. Simultaneously, there was a decrease in the content of antioxidant vitamins C (44%) and E (42%). It was suggested that the iron-induced liver damage in thalassemia may play a major role in the depletion of antioxidant vitamins. Plasma thiobarbituric acid-reactive substances (TBARS) and conjugated dienes were elevated in (3-thalassemic children compared to controls together with compensatory increase in SOD activity [386]. The development of lipid peroxidation in thalassemic erythrocytes probably depends on a decrease in reduced glutathione level and decreased catalase activity [387]. 

C. carpio 10 during exposure for 96 h, significant alterations were recorded in lipid peroxidation rate, hemoglobin concentration, and erythrocyte antioxidant enzymes, that is, catalase, superoxide dismutase, and glutathione peroxidase activities 20... 

Erythrocytes also have systems that can inactivate ROS (superoxide dismutase, catalase, GSH). They are also able to repair damage caused by ROS. This requires products that are supplied by the erythrocytes maintenance metaboiism, which basically only involves anaerobic glycolysis (see p. 150) and the pentose phosphate pathway (PPP see p. 152). 

A synergism between SOD and catalase points to the OH radical (or a OH radical like intermediate) as the toxic species. The damage to resealed erythrocyte ghosts by radiolytically produced OH radicals was enhanced by H Oj by a factor of almost... 

The importance of reaction (13) was also shown with stimulated human neutrophils, which generate OJ and are thus able to lyse erythrocytes. This hemolysis was inhibited by exogenous (Cu,Zn)-SOD in contrast with the heat-denatured enzyme and with catalase. When hemoglobin in the erythrocytes was converted into methemoglobin by a nitrite treatment, SOD became ineffective, but exogenous catalase protected. The erythrocyte became resistant to hemolysis when treated with carbon monoxide, whereby the formation of methemoglobin was blocked and reaction (13) avoided... 

Experiments in which the lysis of erythrocytes exposed to oxidizable organic compounds have also been performed 204-206.213,214) jjj some of these experiments O and H2O2 appear to be involved as shown by the inhibition of lysis by superoxide dismutase and catalase. However, the pathways leading to lysis in these experiments may be complex because of the effects of O and H2O2 on the rates of autoxidation of the organic compounds and because of the possibility that the oxidizable organic compounds or their products react with the red cells directly. 

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