Effect of ethanol amine plasmalogens on Fe-induced peroxidation of arachidonic acid in dipalmitoylphosphatidylcholine vesicles.
We have investigated the influence of ethanolamine plasmalogens on iron-induced oxidation of arachidonic acid in dipalmitoylphosphatidylcholine (DPPC) vesicles. Lipoperoxidation was induced by the addition of 50 microM FeSO4 and studied above (50 degrees C) and below (15 degrees C) the gel-to liquid transition temperature of the vesicles, at two different pH values (7.4 or 6.4). The extent of peroxidation was measured as thiobarbituric reactive product formed and the influence exerted by ethanolamine plasmalogens (PEPL) in this process was compared to that of dipalmitoylphosphatidylethanolamine (DPPE) and diacylphosphatidylethanolamines (DAPE). The extent of peroxidation of arachidonic acid embedded in DPPC vesicles was similar at the two temperatures and greater at 50 degrees C under acidic conditions. However, the peroxidative process was significantly decreased at 50 degrees C in the presence of PEPL, but not of DPPE or DAPE and the inhibitory effect was enhanced at pH 6.4. The possibility that a different phase distribution of the phospholipids, namely a transition from a lamellar to a hexagonal phase, may play a role in the scavenger effect of ethanolamine plasmalogens is discussed.
Omodeo Salè
M F
MF
Istituto di Fisiologia Generale e Chimica Biologica, Facoltà di Farmacia, Milano, Italy. omodeo@mailserver.unimi.it
Rizzo
A M
AM
Masserini
M
M
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D016718:Arachidonic Acid / Q000737:chemistry* / Q000378:metabolism; D001921:Brain / Q000378:metabolism; D002151:Calorimetry; D002417:Cattle; D005296:Ferrous Compounds / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D007700:Kinetics; D015227:Lipid Peroxidation / Q000187:drug effects*; D008081:Liposomes; D010714:Phosphatidylethanolamines / Q000737:chemistry / Q000378:metabolism; D010955:Plasmalogens / Q000737:chemistry* / Q000494:pharmacology; D013696:Temperature
D005296:Ferrous Compounds; D008081:Liposomes; D010714:Phosphatidylethanolamines; D010955:Plasmalogens; C020791:phosphatidal ethanolamines; D015060:1,2-Dipalmitoylphosphatidylcholine; D016718:Arachidonic Acid; C020748:ferrous sulfate; C044820:1,2-diarachidonoyl-glycero-3-phosphoethanolamine