Rapid isolation of lipoproteins and assessment of their peroxidation by high-performance liquid chromatography postcolumn chemiluminescence.

Publisher Summary Peroxidation of polyunsaturated lipids proceeds via a free radical chain reaction with consumption of molecular oxygen and concomitant formation of lipid hydroperoxides as the primary reaction products. These lipid hydroperoxides may undergo a variety of secondary reactions that result in the formation of reactive carbonyl products. Lipid peroxidation is commonly assessed by measurement of lipid hydroperoxides, diene conjugates, oxygen consumption, or secondary reaction products (example, malonylaldehyde and 4-hydroxynonenal. The different methods available vary greatly in their requirement for specialized (and expensive) equipment and, at least for biological systems, in their limitations and number of potential interferences and/or artifacts. This chapter discusses developments in the use of the high-performance liquid chromatography (HPLC) postcolumn chemiluminescence (CL) method 5 for the assessment of lipoprotein lipid peroxidation. Lipoprotein oxidation, particularly that of low-density lipoproteins (LDL), as oxidative LDL modification is thought to represent an early and important step in the development of atherosclerosis. In the HPLC postcolumn CL method, the different classes of unoxidized and oxidized lipids are extracted, separated (from one another and from lipophilic antioxidants) by HPLC, and detected sequentially by UV absorption and CL, respectively.