The influence of phospholipid polar head on the lipid hydroperoxide dependent initiation of lipid peroxidation.
In a buffer (Mes) and at a pH (6.5) where Fe2+ is very stable, we have studied the peroxidation of liposomes catalyzed by FeCl2. The liposomes studied, prepared by sonolysis, contained either phosphatidylcholine or 1:1 molar ratio of phosphatidylcholine and phosphatidic acid. The presence of the negatively charged phospholipid causes: 1) rapid Fe2+ oxidation and oxygen consumption; 2) increased generation of lipid hydroperoxides; 3) decreased generation of thiobarbituric acid-reactive materials; 4) very low inhibition of Fe2+ oxidation and lipid hydroperoxide generation by BHT; 5) inhibition of the termination phase of lipid peroxidation at high FeCl2 concentrations. A hypothesis is proposed to explain the results obtained.
Tadolini
B
B
Dipartimento di Biochimica, Università di Bologna, Italy.
Fiorentini
D
D
Motta
P
P
Cabrini
L
L
Sechi
A M
AM
D005296:Ferrous Compounds / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects*; D008081:Liposomes; D010713:Phosphatidylcholines / Q000494:pharmacology; D010718:Phosphatidylserines / Q000494:pharmacology; D010743:Phospholipids / Q000737:chemistry / Q000494:pharmacology*
D005296:Ferrous Compounds; D008081:Liposomes; D010713:Phosphatidylcholines; D010718:Phosphatidylserines; D010743:Phospholipids