title: Continuous monitoring of in vitro oxidation of human low density lipoprotein.
abstract: The kinetics of the oxidation of human low density lipoprotein (LDL) can be measured continuously by monitoring the change of the 234 nm diene absorption. The time-course shows three consecutive phases, a lag-phase during which the diene absorption increases only weakly, a propagation phase with a rapid increase of the diene absorption and finally a decomposition phase. The increase of the dienes is highly correlated with the increase of MDA or lipid hydroperoxides. The duration of the lag-phase is determined by the endogenous antioxidants contained in LDL (vitamin E, carotenoids, retinylstearate). Water-soluble antioxidants (ascorbic acid, urate) added in micromolar concentrations prolong the lag-phase in a concentration-dependent manner. The determination of the lag-phase is a convenient and objective procedure for determining the susceptibility of LDL from different donors towards oxidation as well as effects of pro- and antioxidants.
authors.affiliation: Institute of Biochemistry, University of Graz, Austria.
authors.forename: H
authors.initials: H
authors.lastname: Esterbauer
authors.forename: G
authors.initials: G
authors.lastname: Striegl
authors.forename: H
authors.initials: H
authors.lastname: Puhl
authors.forename: M
authors.initials: M
authors.lastname: Rotheneder
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000494:pharmacology; D002338:Carotenoids / Q000097:blood; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007700:Kinetics; D008077:Lipoproteins, LDL / Q000097:blood*; D008991:Monitoring, Physiologic; D010084:Oxidation-Reduction; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D014810:Vitamin E / Q000097:blood
chemical_list: D000975:Antioxidants; D008077:Lipoproteins, LDL; D014810:Vitamin E; D002338:Carotenoids