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At least 19 recordsLinked to original sources
PubMed1978

Red cell damage induced by peroxidized microsomes: the relationship between hemolytic activity and peroxide content.

Rat red blood cells will hemolyze if they are present in vitro in mixtures of rat liver microsomes in which lipid peroxidation has been initiated by NADPH. Recent work from this laboratory indicated that a toxic factor not having radical properties could be generated from the lipids of the peroxidizing microsomes. This toxic factor produced prelytic damage in rat red blood cells. In this communication we show that if Ca(++)-aggregated microsomes are first peroxidized and then sedimented by centrifugation, the resuspended peroxidized microsomes are capable of hemolyzing red cells in the absence of any further microsomal lipid peroxidation. This result shows conclusively that the microsomal lipid peroxidation step can be separated from the attack on red cells leading to frank hemolysis. Furthermore, lipids extracted from the peroxidized microsomes with chloroform-methanol account quantitatively for the degree of hemolysis produced. The active hemolytic material could not be detected in resuspended microsomal centrifugates obtained during the first 10 minutes of NADPH-stimulated microsomal lipid peroxidation. It appeared rapidly after 10 minutes. It was maximal at 20 minutes, and fell to a low level of activity by 60 minutes. Peak hemolytic activity correlated with peak generation of lipid soluble peroxides. High, but less than maximal levels of peroxides appearing at 10 minutes did not cause hemolysis, and high, but less than maximal levels remaining at 60 minutes were only weakly hemolytic. The extracted lipoidal material with hemolytic potency is more reactive than hydrogen peroxide in a peroxide assay.

Animals↗
PubMed1992

Activation of complement in normal serum by hydrogen peroxide and hydrogen peroxide-related oxygen radicals produced by activated neutrophils.

Neutrophils activated by soluble particulate stimuli generate superoxide anion and subsequently form hydrogen peroxide and other oxygen radicals. The effect of hydrogen peroxide on the complement system in normal serum was investigated. Treatment of normal serum with hydrogen peroxide resulted in a diminution of the haemolytic activity of the total and alternative complement pathways and the haemolytic titres of C3 and C5 but not of C2, in normal serum. These decreases in complement activity depended on the concentration of hydrogen peroxide added to the serum. Immunoelectrophoretic analysis of hydrogen peroxide-treated serum showed that C3 and C5 proteins were activated. Complement degradation products C3a and C5a were produced in normal serum treated with hydrogen peroxide, and 20 mM EDTA abolished C3a and C5a production in hydrogen peroxide-treated serum but 20 mM Mg-EGTA did not. Catalase completely abolished and dimethylsulphoxide and D-mannitol, hydroxyl radical scavengers, partially inhibited the hydrogen peroxide-mediated complement activation. Hypochlorite, incubated with normal serum, significantly inhibited serum haemolytic activity, and sodium thiosulphate, a reducing agent, abolished the effect of hypochlorite. Normal serum incubated with activated neutrophils showed neutrophil chemotactic activity and decreased serum haemolytic activity, and the addition of catalase or methionine (5 mM) completely abolished the effects of activated neutrophils. These results suggest that hydrogen peroxide activates complement via an alternative pathway of complement activation and that hydroxyl radicals and other hydrogen peroxide-related species such as hypochlorite are most likely involved in hydrogen peroxide-mediated complement activation. Complement activation by oxygen radicals produced by activated neutrophils may be one of the mechanisms by which complement is activated in human immune complex diseases.

Complement Activation↗
PubMed1977

Studies on vitamin E and selenium deficiency in young pigs. II. The hydrogen peroxide hemolysis test and the measure of red cell lipid peroxides as indices of vitamin E and selenium status.

The usefulness of the hydrogen peroxide hemolysis test and the measure of red cell lipid peroxides as indices of vitamin E and selenium deficiency in swine has been evaluated. Results indicated that although the hydrogen peroxide hemolysis test may be of some indication of the vitamin E status, it is not a reliable index of vitamin E deficiency in swine, at least on an individual basis. In contrast, the measure of red cell lipid peroxides can be considered a reliable test for vitamin E deficiency in swine. The hydrogen peroxide hemolysis test and the red cell lipid peroxides were not significantly affected by selenium deficiency.

Animals↗
PubMed1979

Reaction between peroxidized phospholipid and protein: II. Molecular weight and phosphorus content of albumin after reaction with peroxidized cardiolipin.

Peroxidized cardiolipin (diphosphatidylglycerol) reacts covalently with albumin. Incubation of albumin with increasing amounts of peroxidized cardiolipin produces a gradual increase in molecular size. Incubation with a small amount of peroxidized cardiolipin (molar ratio of cardiolipin/albumin 21) produces a mixture of complexes that differs considerably with respect to the number of cardiolipin molecules bound per molecule of albumin. With larger amounts of peroxidized cardiolipin (molar ratios of cardiolipin/albumin 54 and 114), the complexes formed seem to be of a more uniform type since the numbers of cardiolipin molecules bound per molecule of albumin are similar. No polymerization occurs for reactions in which up to at least 15 moles of cardiolipin have become bound per mole of albumin, and 20--25 moles may be found with only very little polymerization. Only when the ratio of peroxidized cardiolipin to albumin was increased to a high value of 314 did polymerization occur. The present findings show that extensive covalent binding of peroxidized cardiolipin to albumin can occur without intermolecular crosslinking of the protein.

Albumins↗
PubMed1979

Elevation of serum lipid peroxide level associated with doxorubicin toxicity and its amelioration by [dl]-alpha-tocopheryl acetate or coenzyme Q10 in mouse (doxorubicin, toxicity, lipid peroxide, tocopherol, coenzyme Q10).

Elevations of serum lipid peroxide levels were demonstrated in mice after an equitoxic dose of doxorubicin. When BDF1 mice were injected with doxorubicin (20 mg/kg body weight, IP), lipid peroxide levels in sera were elevated 1 day after the injection and the levels declined on subsequent days. 5-Fluorouracil (400 mg/kg body weight, IP) never changed the peroxide levels in serum. Furthermore, it was found that the co-administration of [dl]-alpha-tocopheryl acetate or coenzyme Q10 IM strongly inhibited the doxorubicin-induced elevation of lipid peroxides in serum. The effectiveness of [dl]-alpha-tocopheryl acetate or coenzyme Q10 in reducing the lethality of doxorubicin in mice was also confirmed. These results indicate that the measurement of serum 2-thiobarbituric acid-reacting substances provided a useful measurement of lipid peroxide levels, which may be involved in some way with doxorubicin toxicity, and that the administration of antioxidants provide protection against some of the side effects of doxorubicin.

Animals↗
PubMed1992

Peroxide dependent and independent lipid peroxidation: site-specific mechanisms of initiation by chelated iron and inhibition by alpha-tocopherol.

Peroxidation of linoleic acid (LA) was catalyzed by Fenton reagent (H2O2 and Fe2+) in positively charged tetradecyltrimethylammonium bromide (TTAB) micelles, but not in negatively charged sodium dodecylsulfate (SDS) micelles. However, more hydroxyl radicals formed via the Fenton reaction were trapped by N-t-butyl-alpha-phenyl-nitrone (PBN) in SDS micelles than in TTAB micelles. Generation of linoleic acid alkoxy (LO) radicals by Fe2+ via reductive cleavage of linoleic acid hydroperoxide (LOOH) resulted in peroxidation of LA and formation of PBN-LO. adducts in SDS micelles, but not in TTAB micelles. This LOOH dependent lipid peroxidation could be catalyzed in TTAB micelles in the presence of a negatively charged iron chelator, nitrilotriacetic acid (NTA). LO radicals formed by the LOOH dependent Fenton reaction were also trapped by PBN at the surface of TTAB micelles in the presence of NTA, but not in its absence. The consumption of a spin probe, 16-(N-oxyl-4,4'-dimethyloxazolidin-2-yl)stearic acid (16-NS) during the LOOH dependent Fenton reaction in the presence of NTA was higher in TTAB micelles of LA than in those of lauric acid (LauA), although the rates and amounts of LO radicals formed in the two types of fatty acid micelles were similar. The rates of 5-NS consumption in LA and LauA micelles were almost the same, and were lower than the rate of 16-NS in LA micelles. NTA-Fe2+ initiated peroxidation of LA in TTAB micelles without a lag time in the presence of LOOH, but after a lag period, peroxidation occurred without LOOH.(ABSTRACT TRUNCATED AT 250 WORDS)

Electron Spin Resonance Spectroscopy↗
PubMed1979

Peroxidative breakdown of phospholipids in human spermatozoa, spermicidal properties of fatty acid peroxides, and protective action of seminal plasma.

Aerobic incubation of human spermatozoa in the presence of catalytic amounts of ascorbate and ferrous ion results in rapid peroxidative breakdown of sperm phospholipids and fatty acids; most strongly affected are phosphatidyl ethanolamine, ethanolamine plasmalogen, and docosahexanoic acid. Both peroxidation of the endogenous sperm phospholipid and the concurrent loss of motility can be fully prevented, but not reversed, by an "antiperoxidant" factor present in human seminal plasma. Exogenously applied lipid peroxides are powerfully spermicidal. Washed human spermatozoa, at a concentration normally present in semen, treated with as little as 30 nmoles of lipid peroxide/ml become irreversibly immotile within a few minutes. The antiperoxidant factor present in human seminal plasma effectively counteracts the toxic effect of exogenous peroxidized fatty acids upon human spermatozoa, but is unable to restore motility lost by lipid peroxide action.

Chemical Phenomena↗
PubMed1975

The interaction of bovine erythrocyte superoxide dismutase with hydrogen peroxide: chemiluminescence and peroxidation.

Reaction of bovine erythrocyte superoxide dismutase with H2O2 was accompanied by a luminescence whose intensity was a function of the concentration of H2O2 and whose duration was coincident with the inactivation of the enzyme by this reagent. Oxygen, which protected against inactivation, also diminished the luminescence. Several other compounds which prevented the inactivation by H2O2 also modified the luminescence. Thus urate, formate, and triethylamine inhibited luminescence whereas imidazole and xanthine augmented it. These seemingly contrary effects can be explained by assuming that the compounds which protected the enzyme were peroxidized in competition with the sensitive group on the enzyme. The luminescence arises because that group on the enzyme was oxidized to a product in an electronically excited state, which could return to the ground state by emitting light. Imidazole and xanthine gave electronically excited products whose quantum efficiency was greater than that of the group on the enzyme, whereas urate, formate, and triethylamine gave products with much lower luminescent efficiencies. This superoxide dismutase could catalyze the peroxidation of a wide range of compounds, including ferrocytochrome c, luminol, diphenylisobenzofuran, dianisidine, and linoleic acid. In control experiments, boiled enzyme was inactive. This peroxidative activity can lead to unexpected effects when superoxide dismutase is added to H2O2-producing systems, as a probe for the involvement of O2-. Several examples from the literature are cited to illustrate the misinterpretations which this previously unrecognized peroxidative activity can generate.

Animals↗
PubMed1975

Superoxide, hydrogen peroxide, and singlet oxygen in lipid peroxidation by a xanthine oxidase system.

1. Xanthine oxidase acting aerobically upon acetaldehyde was found to cause the peroxidation of linolenate. This was demonstrated by increased absorbance at 233 nm due to diene conjugation and by the detection of a lipid peroxide spot on the thin layer chromatograms. 2. Superoxide dismutase inhibited this lipid peroxidation, as did catalase, thus indicating that both O2- and H2O2 were essential intermediates. Scavengers of singlet oxygen also inhibited the peroxidation of linolenate, whereas scavengers of hydroxyl radical did not. These effects, which were observed in the absence of iron salts, led to the proposal that O2- and H2O2 can directly give rise to a singlet oxygen, as follows: O2- + H2O2 leads to OH- + OH. + O2. 3. This proposal was further supported through the use of 2,5-dimethylfuran, as an indicating scavenger of singlet oxygen. Thus, when this compound was exposed to a known source of singlet oxygen, it gave a product which was detectable by thin layer chromatography. This product was also observed when 2,5-dimethylfuran was exposed to the xanthine oxidase system, in which case its accumulation was prevented by superoxide dismutase or by catalase, but not by scavengers of hydroxyl radical.

Acetaldehyde↗
PubMed1992

Influence of bile acids on stimulated lipid peroxidation and hydrogen peroxide production in rat liver microsomes.

Bile acids were found to be effective antioxidants in bile and intestine. The influence of different bile acids on the NADPH-Fe(++)-stimulated lipid peroxidation (LPO) and cytochrome P-450 dependent hydrogen peroxide production (H2O2) in rat liver microsomes was investigated in vitro. LPO was determined as production of thiobarbituric acid reactants (TBAR). Different tri-, di- and monohydroxylated bile acids and cholesterol were given to the incubation mixture in concentrations ranging from 10(-5) to 10(-3) M. Sodium salts of cholic, tauroglycocholic and deoxycholic acids as well as cheno-deoxycholic, ursodeoxycholic, lithocholic acids and cholesterol did not alter the microsomal production of TBAR. H2O2 formation was significantly decreased by sodium deoxycholate whereas cholesterol increased H2O2 production up to 4 times. These results show that bile acids were not able to protect microsomal membrane lipids against peroxidative damage. Cholesterol mediated H2O2 formation as a source of hydroxyl radicals had no toxic effect concerning LPO, TBAR were not enhanced significantly.

Animals↗
PubMed1979

Instrumentation and techniques for analysis of hydrogen peroxide and peroxide-producing reactions involving earthworm (Diplocardia longa) bioluminescence.

Earthworm bioluminescence (species Diplocardia longa) is a sensitive tool for determination of peroxide titers in biological systems, with linearity of the standard curve for hydrogen peroxide extending from 10 nmol/L in the assay to greater than 1 mmol/L, and with sensitivity to 2 pmol of peroxide per assay. This assay's insensitivity to extraneous protein, turbidity, and solutes that are not redox active makes it particularly useful for automated or crude sample analysis and for analysis of oxidases and their substrates in coupled reactions. Examples of this latter application we discuss are analyses of glucose and putrescine oxidases and their substrates. In each case linear standard curves are obtained, covering several decades of concentration. The coupled reactions also allow in situ detection of oxidases in electrophoresis gels. We also describe a small, portable photometer system and an on-line computer-controlled instrument system that has facilitated development of these assays and will also allow automatic scanning of bioluminescence in gels. The data-collection and decision-making algorithms of this system are simple and easily adaptable for use in an inexpensive computer-based photometer system.

Animals↗
PubMed1979

Inhibition of lipid peroxidation by calcium ions and their protection of steroid hydroxylase activity from peroxidative damage.

Lipid peroxidation of adrenocortical mitochondria and microsomes was greatly stimulated by addition of 1.0 mM or less ferric ions. In the presence of NADPH-yielding system, the formation of corticosterone from endogeneous cholesterol and exogeneous deoxycorticosterone was inhibited as the concentrations of iron increased. Of interest is the fact that 0.5 mM ferric ion-mediated lipid peroxidation was completely abroagated upon addition of 2 mM calcium ions. Accordingly, protected from the peroxidative damage.

Adrenal Cortex↗
PubMed1979

Participation of superoxide, hydrogen peroxide and hydroxyl radicals in NADPH-cytochrome P-450 reductase-catalyzed peroxidation of methyl linolenate.

1. NADPH-cytochrome P-450 reductase-catalyzed peroxidation of methyl linolenate is inhibited by superoxide dismutase, catalase, ethanol, and mannitol, and is potentiated by H2O2. 2. H2O2 is shown to be generated in the incubation mixture in the presence of NADPH and NADPH-cytochrome P-450 reductase. If the system contains Fe-EDTA complex, H2O2 is not formed. In the presence of the enzyme and Fe-EDTA complex, added H2O2 is consumed. 3. In the presence of Fe-EDTA complex, NADPH-cytochrome P-450 reductase is shown to generate O-2 at a slow rate. These results suggest that H2O2 produced from O-2 is decomposed to form OH . by the action of Fe-EDTA complex in the lipid peroxidation system, and that OH . is a trigger of lipid peroxidation.

Catalase↗
PubMed1979

Lipid peroxidation and its inhibition by tinoridine, II. Ascorbic acid-induced lipid peroxidation of rat liver mitochondria.

Incubation of rat liver mitochondrial suspension with ascorbic acid and Fe2+ resulted in the formation of malondialdehyde and a decrease in the turbidity of the suspension. The maximum amount of malondialdehyde formed during the peroxidation reaction was estimated to be 1 mol per approximately 6 mol of mitochondrial phospholipids. Tinoridine and alpha-tocopherol at the concentration of 5 micron and 1 mM, respectively, completely inhibited the peroxidative disintegration of mitochondria. From the relationship between the concentration of tinoridine and the amount of malondialdehyde formed, it was demonstrated that 1 mol of tinoridine prevents the formation of about 6 mol of malondialdehyde. These findings suggest that there is a limit in the chain reaction of the lipid peroxidation of mitochondria and that the limit is the membrane sphere which is capable of releasing 6 molecules of malondialdehyde and contains about 36 molecules of the constitutive phospholipids.

Animals↗
PubMed1992

High correlation between lipid peroxide radical and tumor-promoter effect: suppression of tumor promotion in the Epstein-Barr virus/B-lymphocyte system and scavenging of alkyl peroxide radicals by various vegetable extracts.

We examined the ability of hot-water extracts of 66 vegetables and plants to suppress tumor promotion, as well as to scavenge lipid peroxide radicals in vitro. To assess the effect against tumor promotion (transformation) in vitro, we used the phorbol myristate acetate/Epstein-Barr virus/B-lymphocyte system. To assess the lipid radical-scavenging effect, the luminol-enhanced chemiluminescence method using the tert-butyl hydroperoxide/heme system was used, which generates more alkyl peroxide radical (ROO.) than alkyl (R.) and alkoxyl (RO.) radicals. The results showed a significant correlation between the anti-tumor-promoting effect and the lipid radical-scavenging effect (r = 0.82). We found that boiled extracts of green leaves of carrot, crucifers, and beans (black bean, red bean, mung bean, and soybean) had the greatest anti-tumor-promoter and radical-scavenging activities. Cold-water extracts of vegetables generally exhibited only about 10% or less of the activity of the hot-water extracts.

Antigens, Viral↗
PubMed1992

Vascular cells under peroxide induced oxidative stress: a balance study on in vitro peroxide handling by vascular endothelial and smooth muscle cells.

Enzymes such as glutathione peroxidase and catalase play an important role in the cellular defence against (per)oxidative stress. Balance- and inhibitor-studies were undertaken with in vitro cultured human vascular endothelial cells (EC) and smooth muscle cells (SMC) to assay the relative importance of these enzymes in the handling of cumene hydroperoxide (Chp) and hydrogen peroxide (H2O2). Low concentrations of Chp (up to 80 microM) could be removed to near completion within the first hour of incubation by stimulation of the hexose monophosphate shunt (HMS) of both cell types. The HMS activity reached a plateau upon incubation with higher concentrations of Chp (> 80 microM). The non-converted Chp in the higher concentrations could be detected quantitatively in the incubation solution. After inhibition of the glutathione reductase by 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), incubation with Chp (40 microM) did not result in a stimulation of the HMS activity. Moreover the added Chp could be recovered from the medium. So Chp is exclusively handled by the GSH-redox cycle. When low concentrations of H2O2 (up to 80 microM) were added to EC or SMC approximately 50% of the peroxide loss could not be accounted for. Inhibitor studies with aminotriazole proved that catalase was responsible for the handling of this unaccounted H2O2. In both ECs and SMCs at lower concentrations of H2O2 the GSH-redox cycle was as effective as catalase and at higher H2O2 concentrations the catalase pathway plays the major role.

Benzene Derivatives↗