ASSAYING LOW-DENSITY LIPOPROTEIN OXIDATION BY LASER LIGHT SCATTERING

Publisher Summary The oxidation of human low-density lipoproteins (LDL) results in molecular changes that alter the mechanism of recognition by receptors in target tissues and stimulate the biosynthesis of chemotactic factors activating monocytes, and then macrophage uptake by scavenger receptors when the LDL are widely oxidized. This last event is generally considered an early step in the formation of an atherosclerotic lesion. Thus, it is necessary to take an interest in methods allowing fast and accurate description of the oxidation state of LDL, whatever the oxidation process involved: be it natural, the result of an oxidative stress, or a chemically induced oxidation useful for studying protective effects of antioxidants. The O 2 - and .OH radicals generated by gamma radiolysis constitute a suitable method of LDL peroxidation because of the selectivity of the radicals produced and the quantitative dosimetry, which allows the control of the oxidative damage process. Light-scattering techniques and particularly laser Doppler electrophoresis (LDE) are convenient for describing surface modifications, that is, electrostatic surface charge variations, following oxidation. Moreover, the determination of LDL populations based on the oxidation process could be more informative than the agarose gel technique.