Ethanolamine plasmalogen and cholesterol reduce the total membrane oxidizability measured by the oxygen uptake method.
To investigate the effects of ethanolamine plasmalogen, phosphatidylethanolamine, cholesterol, and alpha-tocopherol on the oxidizability of membranes, various large unilamellar vesicles (LUVs) including these lipids and antioxidant were examined for their total membrane oxidizabilities, evaluated as R(p)/R(i)(1/2) value (where R(p) is rate of oxygen consumption and R(i)(1/2) is the square root of rate of chain initiation) by the oxygen uptake method with water-soluble radical initiator and inhibitor. Incorporation of bovine brain ethanolamine plasmalogen (BBEP) into vesicles as well as cholesterol led to lower the total membrane oxidizability dose-dependently. The effect of BBEP was more efficient in the presence of cholesterol in vesicles. On the other hand, diacyl counterpart, egg yolk phosphatidylethanolamine, and a typical radical scavenger, alpha-tocopherol, had no effect on the membrane oxidizability. Alpha-tocopherol only prolonged an induction period dose-dependently in the present oxidizing system, suggesting a novel antioxidant mechanism of ethanolamine plasmalogens besides the action of scavenging radicals.
Maeba
Ryouta
R
Department of Biochemistry, Teikyo University School of Medicine, Tokyo, Japan. maeba@med.teikyo-u.ac.jp
Ueta
Nobuo
N
D000818:Animals; D002417:Cattle; D002462:Cell Membrane / Q000187:drug effects* / Q000378:metabolism; D002784:Cholesterol / Q000494:pharmacology*; D004338:Drug Combinations; D016166:Free Radical Scavengers; D010084:Oxidation-Reduction / Q000187:drug effects; D010100:Oxygen / Q000378:metabolism*; D010714:Phosphatidylethanolamines / Q000494:pharmacology; D010743:Phospholipids / Q000378:metabolism; D010955:Plasmalogens / Q000494:pharmacology*; D024502:alpha-Tocopherol / Q000494:pharmacology
D004338:Drug Combinations; D016166:Free Radical Scavengers; D010714:Phosphatidylethanolamines; D010743:Phospholipids; D010955:Plasmalogens; C020791:phosphatidal ethanolamines; D002784:Cholesterol; D024502:alpha-Tocopherol; D010100:Oxygen