Oxymyoglobin oxidation as affected by oxidation products of phosphatidylcholine liposomes

Supernatants (105,000 x g) of oxidized phosphatidylcholine (PC) liposomes contained higher levels of thiobarbituric acid-reactive substances, and caused greater metmyoglobin formation when combined with oxymyoglobin than those of controls (C) or PC plus tocopherol (PCT) (P<0.05). Products of PC liposome oxidation crossed dialysis membranes (mel wt cut-off = 500 Dalton) and accelerated the oxidation of oxymyoglobin more than C or PCT (P<0.05). The addition of known oxidation products of oleic acid and linoleic acid, fatty acids typical of PC, accelerated oxymyoglobin oxidation relative to controls (P<0.05). Results demonstrated that oxidation products of PC were prooxidative towards oxymyoglobin.