Oxymyoglobin Oxidation as Affected by Oxidation Products of Phosphatidylcholine Liposomes

Supernatants (105,000 × 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 (mol 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.