Leak formation in human erythrocytes by the radical-forming oxidant t-

Deüticke, B.; Heller, Klaus B.; Haest, C.W.M.

doi:10.1016/0005-2736(86)90108-2

Cited by 80 publications

(24 citation statements)

References 51 publications

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“…Chemical and enzymatic analyses: Oxidative stress was assessed in vitro by treating red blood cells (RBC) with t-butyl hydroperoxide (t-ButOOH) (Deuticke et al, 1986); the haemoglobin oxidative degradation products represented by methaemoglobin were calculated as described by Winterbourn (1990).…”

Section: Methodsmentioning

confidence: 99%

Training-induced modifications in some biochemical defences against free radicals in equine erythrocytes

1995

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Oxidative stress develops when the generation of free radicals exceeds the antioxidant capacity of cells or extracellular fluids. It can also occur as a result of physical exercise, and the pathogenesis of exercise-induced myopathies and haemolysis in horses may be related to changes in lipid peroxidation caused by free radicals. Cells have developed biochemical protection against oxidative stress and, as tissues seem to increase their antioxidant defences under chronic activation, training may be one of the ways of increasing antioxidant defences. Accordingly, we tested some enzymatic antioxidant activities as well as nonenzymatic antioxidants in horses undergoing special training. The results indicated a decrease in both chemical and biochemical defences against free radicals during training. It was deduced that the horses' diet may have been unable to provide the increased need for antioxidant defences resulting from training.

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Section: Methodsmentioning

confidence: 99%

Training-induced modifications in some biochemical defences against free radicals in equine erythrocytes

1995

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“…We exposed 10% cells to 0.5 mM BHP for a relatively short period, as suggested by Deuticke et al [18], and to 2 mM BHP for a longer period. Under these condi tions, we found that mild BHP exposure caused similar Hb oxidation but higher lipid peroxidation in IDA cells.…”

Section: Discussionmentioning

confidence: 99%

Iron Deficiency Anemia: Recovery from in vitro Oxidative Stress

et al. 1993

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Red blood cells in iron deficiency anemia (IDA) have a decreased activity of essential antioxidant enzymes. The present study examined the effect of in vitro exposure to oxidative agents in IDA cells and their recovery capacity. Red cells of 26 IDA patients and 10 healthy subjects were examined. Cells of IDA patients had higher levels of reduced glutathione (GSH), and normal methemoglobin and malonyldialdehyde (MDA) levels. Exposure to butyl hydro-peroxide revealed a dose-dependent sensitivity in IDA cells, with extensive GSH depletion and increased MDA levels. These changes were partially reversible by incubation with dithiothreitol. Exposure to phenazine methosulfate, to produce intracellular superoxide ions, resulted in moderate GSH depletion and methemoglobin production. IDA cells were more sensitive than control cells to high concentrations of this substance. This effect was further augmented by preincubation with a superoxide dismutase inhibitor. Our data demonstrate that IDA cells are more susceptible to oxidation but have good capacity for recovery.

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“…This is shown in Table 2 1978), but also for cells subjected to peroxidative damage by the O2-derived reactive species that are formed when erythrocytes are treated with t-butylhydroperoxide (Deuticke, Heller & Haest, 1986) or with iodoacetate/vanadate/ferricyanide, as discovered recently (Heller, Jahn & Deuticke, 1987). Moreover, noncovalent perturbation of the membrane by channel-formers, such as gramicidin A and amphotericin B, and by local anaesthetics enhances the flip of palmitoylcarnitine.…”

Section: Flip Enhancement Upon Membrane Perturbationmentioning

confidence: 99%

Nonmediated flip-flop of phospholipid analogues in the erythrocyte membrane as probed by palmitoylcarnitine: Basic properties and influence of membrane modification

1989

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The rules governing the transbilayer reorientation (flip-flop) of long-chain amphiphilic components in biological membranes were further elucidated by studying the flip-flop of palmitoylcarnitine in human erythrocytes. Flip rates were derived from the time-dependent decrease of extractability of palmitoylcarnitine by albumin after primary insertion of trace amounts of the labeled probe into the outer membrane layer. The flip rate (half time 2.6 hr at 37 degrees C in human erythrocytes) is fast enough to be measurable also in membranes exhibiting low flip rates such as that of ox erythrocytes. Flip rate constants for the inward and outward reorientation are similar and the probe equilibrates at a 1:1 ratio between the two layers. The flip is a simple, diffusion-like process. It is not inhibited but even enhanced by chemical modification of membrane proteins. It is also enhanced by insertion of channel-forming antibiotics into the membrane and by pre-exposure of the cells to temperatures exceeding 42 degrees C. The extent of this enhancement increases with the duration and the temperature of the pre-exposure. Since spectrin is denatured in this range of temperatures, the finding constitutes a new piece of evidence that the membrane skeleton is involved in the maintenance of bilayer stability and that a decrease of bilayer stability goes along with the formation of local defects acting as flip sites for phospholipids and related compounds. As a particularity, the flip is enhanced by lowering the pH and exhibits interindividual variability, phenomena not observed for the flip-flop of lysophosphatidylcholine. This suggests that generalizations on the kinetics of nonmediated flip-flop of membrane-intercalated amphiphiles may not be justified.

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Leak formation in human erythrocytes by the radical-forming oxidant t-

Cited by 80 publications

References 51 publications

Training-induced modifications in some biochemical defences against free radicals in equine erythrocytes

Training-induced modifications in some biochemical defences against free radicals in equine erythrocytes

Iron Deficiency Anemia: Recovery from in vitro Oxidative Stress

Nonmediated flip-flop of phospholipid analogues in the erythrocyte membrane as probed by palmitoylcarnitine: Basic properties and influence of membrane modification

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