Formation of F2‐isoprostanes during aortic endothelial cell‐mediated oxidation of low density lipoprotein

Abstract
We investigated the formation of F2‐isoprostanes produced by non‐enzymatic peroxidation of arachidonic acid during rabbit aortic endothelial cell‐mediated oxidation of low density lipoprotein (LDL). Free and total (sum of free and esterified) levels of F2‐isoprostanes were measured using a solid‐phase extraction procedure and gas chromatography‐mass spectrometry. Free levels of F2‐isoprostanes in native LDL were 0.06 ± 0.03 ng/mg protein (n = 4), whereas total levels were 0.28 ± 0.09 ng/mg protein (n = 4). Both free and total levels of the isoprostanes were found to increase during the oxidation. 8‐epi‐PGF was the major isoprostane formed (free and total concentrations after 24 h, 2.50 ± 0.24 and 6.42 ± 1.36 ng/mg protein (n = 4), respectively). The release of F2‐isoprostanes during aortic endothelial cell‐induced oxidation of LDL could be a contributory factor in the development of atherosclerosis.