Kinetics of Fatty Acid Oxidation in Low Density Lipoproteins Evaluated by Registration of the Oxidizer Consumption and Reaction Product Yield

Abstract

Oxidation of arachidonic acid by ROS in vitro can be evaluated by the formation of reaction products (conjugated dienes); this is preceded by a lag period caused by the action of antioxidants (alpha-tocopherol, beta-carotene, and ascorbic acid). In case of ozone titration the oxidizer is consumed even during the lag period, when conjugated dienes are not yet forming. Comparison of the oxidation rate constants for antioxidants, arachidonic and oleic monoenic fatty acids suggests that during the lag period Cu(2+)-initiated forms of O(2) oxidize primarily oleic acid, whose reaction rate constant is much higher than those of antioxidants. Presumably, the duration of lag period during oxidation of arachidonic acid and formation of conjugated dienes is determined also by the content of triglycerides and oleic fatty acid in low density lipoproteins.