scholarly journals Superoxide-dependent formation of hydroxyl radicals and lipid peroxidation in the presence of iron salts. Detection of ‘catalytic’ iron and anti-oxidant activity in extracellular fluids

1982 ◽  
Vol 206 (3) ◽  
pp. 605-609 ◽  
Author(s):  
John M. C. Gutteridge ◽  
David A. Rowley ◽  
Barry Halliwell
Keyword(s):  
Lipid Peroxidation ◽  
Molecular Weight ◽  
Hydroxyl Radicals ◽  
Oxygen Radical ◽  
Low Ph ◽  
Radical Reactions ◽  
Iron Catalysts ◽  
Ph Values ◽  
Iron Salts ◽  
Anti Oxidant

Synovial fluid from rheumatoid patients and normal cerebrospinal fluid contains micromolar concentrations of non-protein-bound iron salts that can promote lipid peroxidation and also the superoxide-dependent formation of hydroxyl radicals from hydrogen peroxide. These iron catalysts of oxygen radical reactions cannot be detected by conventional assays unless interfering high-molecular-weight substances, probably proteins, are removed by ultrafiltration or inactivated by exposure to low pH values. The bleomycin assay for ‘catalytic’ iron [Gutteridge, Rowley & Halliwell (1981) Biochem. J.199, 263–265] does not suffer from these artifacts.

Low-molecular-weight iron complexes and oxygen radical reactions in idiopathic haemochromatosis

1985 ◽  
Vol 68 (4) ◽  
pp. 463-467 ◽  
Author(s):  
J. M. C. Gutteridge ◽  
D. A. Rowley ◽  
E. Griffiths ◽  
B. Halliwell
Keyword(s):  
Molecular Weight ◽  
Iron Overload ◽  
Membrane Lipids ◽  
Iron Complexes ◽  
Iron Chelator ◽  
Oxygen Radical ◽  
Radical Reactions ◽  
Low Molecular Weight ◽  
Iron Salts ◽  
Low Molecular Weight Iron

1. The sera of patients with idiopathic haemochromatosis and iron-overload have been found to contain low-molecular-weight iron complexes detectable in the ‘bleomycin assay'. 2. These complexes stimulate both the peroxidation of membrane lipids and the formation of the highly reactive and damaging hydroxyl radical. 3. The iron chelator desferrioxamine interferes with these reactions. 4. We suggest that oxygen radical reactions stimulated by iron salts are important in the pathology of idiopathic haemochromatosis.

Lipid peroxidation in rheumatoid arthritis: Thiobarbituric acid-reactive material and catalytic iron salts in synovial fluid from rheumatoid patients

1984 ◽  
Vol 66 (6) ◽  
pp. 691-695 ◽  
Author(s):  
David Rowley ◽  
John M. C. Gutteridge ◽  
David Blake ◽  
Margaret Farrs ◽  
Barry Halliwell
Keyword(s):  
Rheumatoid Arthritis ◽  
Lipid Peroxidation ◽  
Synovial Fluid ◽  
Knee Joint ◽  
Thiobarbituric Acid ◽  
Radical Reactions ◽  
Local Inflammation ◽  
Reactive Material ◽  
Iron Salts

1. Thiobarbituric acid (TBA)-reactive material is present in serum and knee joint synovial fluid from rheumatoid patients, consistent with lipid peroxidation occurring in vivo. 2. The amount of TBA-reactive material in synovial fluid correlates with the concentration of iron salts present as determined by the bleomycin method, presumably because iron is an important catalyst of radical reactions in vivo. 3. There appear to be significant correlations between the contents of TBA-reactive material and bleomycindetectable iron in synovial fluid and the activity of rheumatoid arthritis as assessed with a clinical index of local inflammation and with various laboratory parameters.

scholarly journals Formation of hydroxyl radicals in the presence of ferritin and haemosiderin. Is haemosiderin formation a biological protective mechanism?

1986 ◽  
Vol 234 (3) ◽  
pp. 727-731 ◽  
Author(s):  
M O'Connell ◽  
B Halliwell ◽  
C P Moorhouse ◽  
O I Aruoma ◽  
H Baum ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Iron Overload ◽  
Hydroxyl Radicals ◽  
Oxygen Radical ◽  
Radical Reactions ◽  
Protective Mechanism ◽  
Reaction Conditions ◽  
Human Spleen

Horse spleen and human spleen ferritins increase the formation of hydroxyl radicals (OH) at both pH 4.5 and pH 7.4 in reaction mixtures containing ascorbic acid and H2O2. The generation of OH is inhibited by the chelator desferrioxamine. Human spleen haemosiderin also accelerates OH generation in identical reaction mixtures, but is far less effective (on a unit iron basis) than ferritin under all reaction conditions. It is proposed that conversion of ferritin into haemosiderin in iron overload is biologically advantageous in that it decreases the ability of iron to promote oxygen-radical reactions.

scholarly journals Bleomycin-detectable iron in knee-joint synovial fluid from arthritic patients and its relationship to the extracellular antioxidant activities of caeruloplasmin, transferrin and lactoferrin

1987 ◽  
Vol 245 (2) ◽  
pp. 415-421 ◽  
Author(s):  
J M C Gutteridge
Keyword(s):  
Knee Joint ◽  
Antioxidant Activities ◽  
Lipid Peroxide ◽  
Oxygen Radical ◽  
Low Ph ◽  
Acidic Ph ◽  
Peroxide Content ◽  
Ph Values ◽  
Synovial Fluids ◽  
Radical Damage

Some 40% of knee-joint synovial fluids from arthritic patients show the presence of bleomycin-detectable iron. This is released from a protein component of the fluid to bleomycin at acidic pH values. Patients whose fluids release iron have lower contents of transferrin, lactoferrin and caeruloplasmin than do patients whose fluids do not release iron to bleomycin. These proteins are important extracellular antioxidants, and measured antioxidant activities are extremely low in the iron-releasing fluids. The propensity of some fluids to release iron at low pH values, characteristic of the microenvironment beneath adherent macrophages, coupled with their decreased antioxidant protection against iron-stimulated oxygen-radical damage, might explain previously reported correlations between clinical disease severity, lipid peroxide content and the presence of bleomycin-detectable iron [Rowley, Gutteridge, Blake, Farr & Halliwell (1984) Clin. Sci. 66, 691-695].

scholarly journals Inhibition of the iron-catalysed formation of hydroxyl radicals from superoxide and of lipid peroxidation by desferrioxamine

1979 ◽  
Vol 184 (2) ◽  
pp. 469-472 ◽  
Author(s):  
J M C Gutteridge ◽  
R Richmond ◽  
B Halliwell
Keyword(s):  
Lipid Peroxidation ◽  
Ascorbic Acid ◽  
Acetic Acid ◽  
Hydroxyl Radicals ◽  
Iron Chelator ◽  
Clinical Use ◽  
Membrane Phospholipids ◽  
Iron Salt ◽  
Iron Salts

The peroxidation of membrane phospholipids induced in vitro by ascorbic acid or by dialuric acid (hydroxybarbituric acid) does not occur in the absence of traces of metal ions. Peroxidation induced by adding iron salts to phospholipids can either be promoted or inhibited by the chelators EDTA, diethylenetriaminepenta-acetic acid and bathophenanthrolinesulphonate, depending on the ratio [chelator]/[iron salt]. The iron chelator desferrioxamine inhibits peroxidation at all concentrations tested, and it also inhibits the iron-catalysed formation of hydroxyl radicals (OH.) from superoxide (O2-.). Since desferrioxamine is approved for clinical use, it might prove a valuable tool in the treatment of inflammation, poisoning by autoxidizable molecules and radiation damage.

scholarly journals Antioxidant protection by haemopexin of haem-stimulated lipid peroxidation

1988 ◽  
Vol 256 (3) ◽  
pp. 861-865 ◽  
Author(s):  
J M Gutteridge ◽  
A Smith
Keyword(s):  
Lipid Peroxidation ◽  
Protoporphyrin Ix ◽  
Thiobarbituric Acid ◽  
Iron Chelator ◽  
Oxygen Radical ◽  
Butylated Hydroxytoluene ◽  
Radical Reactions ◽  
Antioxidant Protection ◽  
Reactive Material ◽  
Chain Breaking

Haem (ferrous protoporphyrin IX) is a reactive low-molecular-mass form of iron able to participate in oxygen-radical reactions that can lead to the degradation of proteins, lipids, carbohydrates and DNA. Oxygen-radical reactions are likely to occur upon tissue damage. Extracellular fluids rely on antioxidant mechanisms different from those found inside the cell, and circulating proteins limit radical reactions by converting pro-oxidant forms of iron into less-reactive forms. Of the compounds tested, only apohaemopexin and the chain-breaking antioxidant butylated hydroxytoluene inhibited (by more than 90%) haemin-stimulated peroxidation as measured by formation of conjugated dienes, thiobarbituric acid-reactive material from linolenic acid or peroxidation-induced phospholipid fluorescence. Haptoglobin, the haemoglobin-binding serum protein, was ineffective. Conversely, only haptoglobin significantly inhibited haemoglobin-stimulated lipid peroxidation. Iron-salt-induced lipid peroxidation was inhibited only by apotransferrin and the iron-chelator desferrioxamine. All lipid peroxidations were inhibited by the radical scavengers butylated hydroxytoluene and propyl gallate. These findings support the concept that transport and conservation of body iron stores are closely linked to antioxidant protection.

Inhibition of Copper-Associated Erythrocyte Ghost Membrane Lipid Peroxidation by Hepatic Cytosolic Low Molecular Weight Proteins

1991 ◽  
Vol 19 (3) ◽  
pp. 206-213
Author(s):  
Bruce L. Homer ◽  
Kenneth R. Pierce ◽  
Charles H. Bridges ◽  
James E. Womack ◽  
Blair A. Sowa ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Molecular Weight ◽  
Membrane Lipid ◽  
Erythrocyte Ghost ◽  
Low Molecular Weight ◽  
Membrane Lipid Peroxidation ◽  
Low Molecular Weight Proteins

scholarly journals Adaptation of Lactobacillus plantarum IMDO 130201, a Wheat Sourdough Isolate, to Growth in Wheat Sourdough Simulation Medium at Different pH Values through Differential Gene Expression

2011 ◽  
Vol 77 (10) ◽  
pp. 3406-3412 ◽  
Author(s):  
Gino Vrancken ◽  
Luc De Vuyst ◽  
Tom Rimaux ◽  
Joke Allemeersch ◽  
Stefan Weckx
Keyword(s):  
Gene Expression ◽  
Lactobacillus Plantarum ◽  
Differential Gene Expression ◽  
Lipoteichoic Acid ◽  
Low Ph ◽  
Exponential Growth Phase ◽  
Cellular Mechanisms ◽  
Content Type ◽  
Ph Values ◽  
Differential Gene

ABSTRACTSourdough is a very competitive and challenging environment for microorganisms. Usually, a stable microbiota composed of lactic acid bacteria (LAB) and yeasts dominates this ecosystem. Although sourdough is rich in carbohydrates, thus providing an ideal environment for microorganisms to grow, its low pH presents a particular challenge. The nature of the adaptation to this low pH was investigated forLactobacillus plantarumIMDO 130201, an isolate from a laboratory wheat sourdough fermentation. Batch fermentations were carried out in wheat sourdough simulation medium, and total RNA was isolated from mid-exponential-growth-phase cultures, followed by differential gene expression analysis using a LAB functional gene microarray. At low pH values, an increased expression of genes involved in peptide and amino acid metabolism was found as well as that of genes involved in plantaricin production and lipoteichoic acid biosynthesis. The results highlight cellular mechanisms that allowL. plantarumto function at a low environmental pH.

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