scholarly journals Subcellular distribution of superoxide dismutases in human neutrophils. Influence of myeloperoxidase on the measurement of superoxide dismutase activity

1977 ◽  
Vol 166 (2) ◽  
pp. 145-153 ◽  
Author(s):  
Richard F. Rest ◽  
John K. Spitznagel
Keyword(s):  
Molecular Weight ◽  
Superoxide Dismutase ◽  
Cytochrome C ◽  
Mitochondrial Fraction ◽  
Superoxide Dismutase Activity ◽  
Human Neutrophils ◽  
Mitochondrial Superoxide ◽  
Ferrocytochrome C ◽  
Azurophil Granule ◽  
Enzyme Superoxide Dismutase

We have identified two distinct pools of superoxide dismutase in fractions of human peripheral neutrophils obtained by the isopycnic fractionation of homogenates of the latter with linear sucrose gradients. Superoxide dismutase activity, observed with polyacrylamide gels impregnated with Nitro Blue Tetrazolium, was present in: (1) the mitochondrial fraction [density (ρ) 1.169g/ml], containing the high-molecular-weight KCN-resistant enzyme, and (2) the cytoplasm fraction, containing the low-molecular-weight KCN-sensitive enzyme. Superoxide dismutase activity, observed with a quantitative assay involving cytochrome c, was present in: (1) the mitochondria, (2) the cytoplasm, and (3) the azurophil-granule fractions (ρ=1.206 and 1.222g/ml). No substantial enzyme activity was observed in specific-granule fractions (ρ=1.187g/ml) or in the membranous fraction (ρ=1.136g/ml) in either assay. The apparent superoxide dismutase activity observed in the azurophil granules with the cytochrome c assay was attributable not to true superoxide dismutase but to myeloperoxidase, an enzyme found solely in the azurophil granules. In the presence of H2O2, human neutrophil myeloperoxidase oxidized ferrocytochrome c. Thus, in the cytochrome c assay for superoxide dismutase, the oxidation of ferrocytochrome c by myeloperoxidase mimicked the inhibition of reduction of ferricytochrome c by superoxide dismutase. When myeloperoxidase was removed from azurophilgranule fractions by specific immuno-affinity chromatography, both myeloperoxidase and apparent superoxide dismutase activities were removed. It is concluded that there is no detectable superoxide dismutase in either the azurophil or specific granules of human neutrophils. Mitochondrial superoxide dismutase, 15% of the total dismutase activity of the cells, occurred only in fractions of density 1.160g/ml, where isocitrate dehydrogenase and cytochrome oxidase were also observed.

Diazoxide Modulates Cardiac Hypertrophy by Targeting H2O2 Generation and Mitochondrial Superoxide Dismutase Activity

2020 ◽  
Vol 13 (1) ◽  
pp. 76-83
Author(s):  
Aline Maria Brito Lucas ◽  
Joana Varlla de Lacerda Alexandre ◽  
Maria Thalyne Silva Araújo ◽  
Cicera Edna Barbosa David ◽  
Yuana Ivia Ponte Viana ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Superoxide Dismutase ◽  
Cardiac Hypertrophy ◽  
Superoxide Dismutase Activity ◽  
Heart Weight ◽  
Pharmacological Intervention ◽  
Wall Thickening ◽  
H2o2 Production ◽  
Mitochondrial Superoxide ◽  
Mitochondrial Superoxide Dismutase

Background: Cardiac hypertrophy involves marked wall thickening or chamber enlargement. If sustained, this condition will lead to dysfunctional mitochondria and oxidative stress. Mitochondria have ATP-sensitive K+ channels (mitoKATP) in the inner membrane that modulate the redox status of the cell. Objective: We investigated the in vivo effects of mitoKATP opening on oxidative stress in isoproterenol- induced cardiac hypertrophy. Methods: Cardiac hypertrophy was induced in Swiss mice treated intraperitoneally with isoproterenol (ISO - 30 mg/kg/day) for 8 days. From day 4, diazoxide (DZX - 5 mg/kg/day) was used in order to open mitoKATP (a clinically relevant therapy scheme) and 5-hydroxydecanoate (5HD - 5 mg/kg/day) or glibenclamide (GLI - 3 mg/kg/day) were used as mitoKATP blockers. Results: Isoproterenol-treated mice had elevated heart weight/tibia length ratios (HW/TL). Additionally, hypertrophic hearts had elevated levels of carbonylated proteins and Thiobarbituric Acid Reactive Substances (TBARS), markers of protein and lipid oxidation. In contrast, mitoKATP opening with DZX avoided ISO effects on gross hypertrophic markers (HW/TL), carbonylated proteins and TBARS, in a manner reversed by 5HD and GLI. Moreover, DZX improved mitochondrial superoxide dismutase activity. This effect was also blocked by 5HD and GLI. Additionally, ex vivo treatment of isoproterenol- induced hypertrophic cardiac tissue with DZX decreased H2O2 production in a manner sensitive to 5HD, indicating that this drug also acutely avoids oxidative stress. Conclusion: Our results suggest that diazoxide blocks oxidative stress and reverses cardiac hypertrophy. This pharmacological intervention could be a potential therapeutic strategy to prevent oxidative stress associated with cardiac hypertrophy.

scholarly journals Effects of Medium Molecular Weight Heparinyl Phenylalnine on Superoxide Dismutase Activity in Mice

In Vivo ◽  
2016 ◽  
Vol 30 (6) ◽  
pp. 841-844
Author(s):  
SEIICHI TAKEDA ◽  
TAKAO TODA ◽  
KAZUKI NAKAMURA
Keyword(s):  
Molecular Weight ◽  
Superoxide Dismutase ◽  
Superoxide Dismutase Activity

Superoxide Dismutase Activity in Bovine Milk Serum

1979 ◽  
Vol 42 (11) ◽  
pp. 867-871 ◽  
Author(s):  
M. KORYCKA-DAHL ◽  
T. RICHARDSON ◽  
C. L. HICKS
Keyword(s):  
Superoxide Dismutase ◽  
Cytochrome C ◽  
Polyacrylamide Gel Electrophoresis ◽  
Bovine Milk ◽  
Enzymic Activity ◽  
Superoxide Dismutase Activity ◽  
Bovine Erythrocyte ◽  
Milk Serum ◽  
Erythrocyte Superoxide Dismutase ◽  
Acid Whey

Superoxide dismutase activity was shown to be present in bovine milk serum and was quantified by measuring the capacity of retentate from dialyzed milk serum to inhibit reduction of cytochrome c by xanthine-xanthine oxidase-generated superoxide anion. One unit of enzyme was defined as the quantity of superoxide dismutase which inhibits cytochrome c reduction by 20%. By this definition 19,500 units of enzyme were present per liter of retentate from dialyzed milk serum. This amount is equivalent to about 2.4 mg of purified bovine erythrocyte superoxide dismutase per liter. Polyacrylamide gel electrophoresis of a partially-purified superoxide dismutase from acid whey, followed by staining for enzymic activity, confirmed the presence of the enzyme in milk serum which was identical in electrophoretic properties to those of bovine erythrocyte copper-zinc superoxide dismutase. Pasteurization at 63 C for 30 min did not decrease superoxide dismutase activity in milk serum. Heating of purified bovine erythrocyte-superoxide dismutase at 100 C for 1 min resulted in almost complete loss of enzymic activity, whereas the partially-purified superoxide dismutase from acid whey still retained 40% of the original activity under these conditions. Bovine milk superoxide dismutase may be an important naturally-occurring antioxidant for increasing oxidative stability of milk and other dairy products.

Characteristics of low molecular weight substances regulating plasma superoxide dismutase activity

1994 ◽  
Vol 17 (4) ◽  
pp. 351-353 ◽  
Author(s):  
Elene E. Dubinina ◽  
Irina V. Shugaley ◽  
Alexander T. Melenevsky ◽  
Igor V. Tselinskii
Keyword(s):  
Molecular Weight ◽  
Superoxide Dismutase ◽  
Superoxide Dismutase Activity ◽  
Low Molecular Weight

Low molecular weight substances regulating plasma superoxide dismutase activity

1993 ◽  
Vol 15 (5) ◽  
pp. 473
Author(s):  
Elena E. Dubinina ◽  
Irina V. Shugaley ◽  
Alexander T. Melenvsky ◽  
Igor V. Tselinskii
Keyword(s):  
Molecular Weight ◽  
Superoxide Dismutase ◽  
Superoxide Dismutase Activity ◽  
Low Molecular Weight
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