Cromoglycate markedly activates ascorbate-ADP initiated lipid peroxidation in washed rat liver microsomes

1993 ◽  
Vol 21 (4) ◽  
pp. 418S-418S
Author(s):  
TASHA GANDAMIHARDJA ◽  
TERENCE HALLINAN ◽  
JAYESH GOR ◽  
CATHERINE RICE-EVANS
Keyword(s):  
Lipid Peroxidation ◽  
Rat Liver ◽  
Liver Microsomes ◽  
Rat Liver Microsomes

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 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.

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.

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