scholarly journals Separation and characterization of the aldehydic products of lipid peroxidation stimulated by ADP-Fe2+ in rat liver microsomes

1982 ◽  
Vol 208 (1) ◽  
pp. 129-140 ◽  
Author(s):  
H Esterbauer ◽  
K H Cheeseman ◽  
M U Dianzani ◽  
G Poli ◽  
T F Slater
Keyword(s):  
Lipid Peroxidation ◽  
Rat Liver ◽  
Liver Microsomes ◽  
Thiobarbituric Acid ◽  
Polar Fraction ◽  
Supernatant Fraction ◽  
Major Type ◽  
Rat Liver Microsomes ◽  
Acid Reaction ◽  
The Individual

1. Methods using t.l.c. and high-pressure liquid chromatography (h.p.l.c.) have been used to separate the complex variety of substances possessing a carbonyl function that are produced during lipid peroxidation. 2. The major type of lipid peroxidation studied was the ADP-Fe2+-stimulated peroxidation of rat liver microsomal phospholipids. Preliminary separation of the polar and non-polar products was achieved by t.l.c.: further separation and identification of individual components was performed by h.p.l.c. Estimations were performed on microsomal pellets and the supernatant mixture after incubation of microsomes for 30 min at 37 degrees C. 3. The polar fraction was larger than the non-polar fraction when expressed as nmol of carbonyl groups/g of liver. In the non-polar supernatant fraction the major contributors were n-alkanals (31% of the total), alpha-dicarbonyl compounds (22%) and 4-hydroxyalkenals (37%) with the extraction method used. 4. Major individual contributors to the non-polar fraction were found to be propanal, 4-hydroxynonenal, hexanal and oct-2-enal. Other components identified include butanal, pent-2-enal, hex-2-enal, hept-2-enal, 4-hydroxyoctenal and 4-hydroxyundecenal. The polar carbonyl fraction was less complex than the non-polar fraction, although the identities of the individual components have not yet been established. 5. Since these carbonyl compounds do not react significantly in the thiobarbituric acid reaction, which largely demonstrates the presence of malonaldehyde, it is concluded that considerable amounts of biologically reactive carbonyl derivatives are released in lipid peroxidation and yet may not be picked up by the thiobarbituric acid reaction.

Lipid Peroxidation and Cherniluminescence during Naproxen Metabolism in Rat Liver Microsomes

1994 ◽  
Vol 13 (12) ◽  
pp. 831-838 ◽  
Author(s):  
Hiroyuki Yokoyama ◽  
Toshiharu Horie ◽  
Shoji Awazu
Keyword(s):  
Lipid Peroxidation ◽  
Singlet Oxygen ◽  
Rat Liver ◽  
Liver Microsomes ◽  
Thiobarbituric Acid ◽  
Rat Liver Microsomes ◽  
Oxygen Species ◽  
Thiobarbituric Acid Reactive Substances ◽  
Microsomal Suspension ◽  
Weight Protein

1 Rat liver microsomal suspension containing NADPH and MgCl2 was incubated at 37°C with naproxen, a non-steroidal anti-inflammatory drug. Thiobarbituric acid reactive substances (TBA-RS), high molecular weight protein aggregates and fluorescent substances were formed in the microsomal suspension. 2 Chemiluminescence was produced from the microsomal suspension. This chemiluminescence production was well correlated to the TBA-RS formation, indicating that the chemiluminescence production was closely associated with the lipid peroxidation. 3 The addition of SKF-525A to the microsomal suspension inhibited the production of TBA-RS, chemiluminescence and 6-demethylnaproxen (6-DMN), the oxidative product of naproxen. Further, the antioxidant, α-tocopherol and singlet oxygen quenchers like histidine, dimethylfuran and 1,4-diazabicyclo[2,2,2]octane strikingly inhibited the productions of chemiluminescence and TBA-RS. 4 Neither naproxen nor 6-DMN caused lipid peroxidation in the absence of NADPH. Thus, lipid peroxidation and chemiluminescence during the oxidation of naproxen in liver microsomes was suggested to be provoked by reactive oxygen species and an origin of chemiluminescence was shown to be singlet oxygen.

scholarly journals Inhibition of microsomal lipid peroxidation by glutathione and glutathione transferases B and AA. Role of endogenous phospholipase A2

1984 ◽  
Vol 220 (1) ◽  
pp. 243-252 ◽  
Author(s):  
K H Tan ◽  
D J Meyer ◽  
J Belin ◽  
B Ketterer
Keyword(s):  
Lipid Peroxidation ◽  
Phospholipase A2 ◽  
Rat Liver ◽  
Inhibitory Activity ◽  
Liver Microsomes ◽  
Supernatant Fraction ◽  
Rat Liver Microsomes ◽  
Microsomal Lipid Peroxidation ◽  
Soluble Supernatant

Lipid peroxidation in vitro in rat liver microsomes (microsomal fractions) initiated by ADP-Fe3+ and NADPH was inhibited by the rat liver soluble supernatant fraction. When this fraction was subjected to frontal-elution chromatography, most, if not all, of its inhibitory activity could be accounted for by the combined effects of two fractions, one containing Se-dependent glutathione (GSH) peroxidase activity and the other the GSH transferases. In the latter fraction, GSH transferases B and AA, but not GSH transferases A and C, possessed inhibitory activity. GSH transferase B replaced the soluble supernatant fraction as an effective inhibitor of lipid peroxidation in vitro. If the microsomes were pretreated with the phospholipase A2 inhibitor p-bromophenacyl bromide, neither the soluble supernatant fraction nor GSH transferase B inhibited lipid peroxidation in vitro. Similarly, if all microsomal enzymes were heat-inactivated and lipid peroxidation was initiated with FeCl3/sodium ascorbate neither the soluble supernatant fraction nor GSH transferase B caused inhibition, but in both cases inhibition could be restored by the addition of porcine pancreatic phospholipase A2 to the incubation. It is concluded that the inhibition of microsomal lipid peroxidation in vitro requires the consecutive action of phospholipase A2, which releases fatty acyl hydroperoxides from peroxidized phospholipids, and GSH peroxidases, which reduce them. The GSH peroxidases involved are the Se-dependent GSH peroxidase and the Se-independent GSH peroxidases GSH transferases B and AA.

scholarly journals Phospholipid exchange reactions within the liver cell

1969 ◽  
Vol 112 (1) ◽  
pp. 91-108 ◽  
Author(s):  
W. C. McMurray ◽  
R. M. C. Dawson
Keyword(s):  
Phosphatidic Acid ◽  
Rat Liver ◽  
Liver Cell ◽  
Mitochondrial Membrane ◽  
Liver Microsomes ◽  
Supernatant Fraction ◽  
Rat Liver Mitochondria ◽  
Rat Liver Microsomes ◽  
The Individual

1. Isolated rat liver mitochondria do not synthesize labelled phosphatidylcholine from CDP-[14C]choline or any phospholipid other than phosphatidic acid from [32P]phosphate. The minimal labelling of phosphatidylcholine and other phosphoglycerides can be attributed to microsomal contamination. However, when mitochondria and microsomes are incubated together with [32P]phosphate, the phosphatidylcholine, phosphatidylinositol and phosphatidylethanolamine of the reisolated mitochondria become labelled, suggesting a transfer of phospholipids between the two fractions. 2. When liver microsomes or mitochondria containing labelled phosphatidylcholine are independently incubated with the opposite un-labelled fraction, there is a substantial and rapid exchange of the phospholipid between the two membranes. Exchange of phosphatidylinositol also occurs rapidly, whereas phosphatidylethanolamine and phosphatidic acid exchange only slowly. There is no corresponding transfer of marker enzymes. The transfer of phosphatidylcholine does not occur at 0°, and there is no requirement for added substrate, ATP or Mg2+, but the omission of a heat-labile supernatant fraction markedly decreases the exchange. 3. After intravenous injection of [32P]phosphate, short-period labelling experiments of the individual phospholipids of rat liver microsomes and mitochondria in vivo give no evidence for a similar exchange process. However, the incubation of isolated microsomes and mitochondria with [32P]phosphate also fails on reisolation of the fractions to demonstrate a precursor–product relationship between the individual phospholipids of the two membranes. 4. The intraperitoneal injection of [32P]phosphate results in a far greater proportion of the dose entering the liver than does intravenous administration. After intraperitoneal administration of [32P]phosphate the specific radioactivities of the individual phospholipids are in the order microsomes > outer mitochondrial membrane > inner mitochondrial membrane. 5. The incorporation of 32P into cardiolipin is very slow both in vivo and in vitro. After labelling in vivo the radioactivity in the cardiolipin persists compared with that of the other phospholipids, whose specific radioactivities in the microsomes and mitochondrial fragments decay at a similar rate to that of the acid-soluble phosphate pool. 6. The possibility of phospholipid exchange processes occurring in the liver cell in vivo is discussed, and it is suggested that only a small but highly labelled part of the endoplasmic-reticulum lipoprotein pool is involved in the transfer.

Antioxidant and Antifungal Properties of Benzimidazole Derivatives

2010 ◽  
Vol 65 (9-10) ◽  
pp. 537-542 ◽  
Author(s):  
Canan Kuş ◽  
Fatma Sözüdönmez ◽  
Benay Can-Eke ◽  
Tülay Çoban
Keyword(s):  
Lipid Peroxidation ◽  
Free Radical ◽  
Radical Scavenging ◽  
Liver Microsomes ◽  
Thiobarbituric Acid ◽  
Benzimidazole Derivatives ◽  
Rat Liver Microsomes ◽  
Inhibitory Effects ◽  
Stable Free Radical ◽  
Radical Scavenging Properties

Antioxidant and radical scavenging properties of a series of 2-[4-(substituted piperazin-/ piperidin-1-ylcarbonyl)phenyl]-1H-benzimidazole derivatives were examined. Free radical scavenging properties of compounds 11-30 and 33 were evaluated for the stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide anion radical. In addition the inhibitory effects on the NADPH-dependent lipid peroxidation levels were determined by measuring the formation of 2-thiobarbituric acid reactive substances (TBARS) using rat liver microsomes. Compound 33 which has a p-fluorobenzyl substitutent at position 1 exhibited the strongest inhibition (83%) of lipid peroxidation at a concentration of 10-3 M, while the nonsubstituted analogue 13 caused 57% inhibition. This result is fairly consistent with the antimicrobial activity results against both Staphylococcus aureus and Candida albicans.

scholarly journals The stimulatory effects of asbestos on NADPH-dependent lipid peroxidation in rat liver microsomes

1987 ◽  
Vol 241 (2) ◽  
pp. 561-565 ◽  
Author(s):  
M Fontecave ◽  
D Mansuy ◽  
M Jaouen ◽  
H Pezerat
Keyword(s):  
Lipid Peroxidation ◽  
Rat Liver ◽  
Active Sites ◽  
Oxygen Radicals ◽  
Liver Microsomes ◽  
Rat Liver Microsomes ◽  
Iron Ions ◽  
Ferrous Ions ◽  
Solid Iron ◽  
Ferric Oxides

Lipid peroxidation in rat liver microsomes induced by asbestos fibres, crocidolite and chrysotile, is greatly increased in the presence of NADPH, leading to malondialdehyde levels comparable with those induced by CCl4, a very strong inducer of lipid peroxidation. This synergic effect only occurs during the first minutes and could be explained by an increase or a regeneration of the ferrous active sites of asbestos by NADPH, which in turn could rapidly be prevented by the adsorption of microsomal proteins on the surface of the fibres. It is not inhibited by superoxide dismutase, catalase and mannitol, indicating that oxygen radicals are not involved in the reaction. It is also not inhibited by desferrioxamine, indicating that it is not due to a release of free iron ions in solution from the fibres. Lipid peroxidation in NADPH-supplemented microsomes is also greatly increased upon addition of magnetite. This could be linked to the presence of ferrous ions in this solid iron oxide, since the ferric oxides haematite and goethite are completely inactive.

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