Mechanistic aspects of the relationship between low-level chemiluminescence and lipid peroxides in oxidation of low-density lipoprotein.
In this study oxidation of low-density lipoprotein (LDL) induced by different Cu2+ concentrations was investigated. Lipid peroxidation was assessed by monitoring low-level chemiluminescence (LL-CL), conjugated diene hydroperoxide (CD) and alpha-tocopherol (TocOH), the major lipophilic antioxidant in LDL. At high Cu2+ concentration, LDL oxidation was characterised by CD formation, LL-CL emission and TocOH consumption. At low Cu2+ concentration, CD formation was independent of LL-CL and occurred in the presence of TocOH. Thus, two different mechanisms lead to lipid peroxide formation in LDL. The combination of CD assay and LL-CL monitoring makes it possible to distinguish the autocatalytic mechanism of CD formation and that associated with TocOH, found at a high and a low rate of initiation, respectively.
Albertini
R
R
Department of Experimental and Clinical Biomedical Sciences, University of Insubria, Via Dunant, 21100, Varese, Italy.
De Luca
G
G
Palladini
G
G
Passi
A
A
Melzi d'Eril
G V
GV
Abuja
P M
PM
D000328:Adult; D003300:Copper / Q000737:chemistry; D005260:Female; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D015227:Lipid Peroxidation; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008163:Luminescent Measurements; D008297:Male; D010084:Oxidation-Reduction; D013997:Time Factors; D014810:Vitamin E / Q000737:chemistry
D008077:Lipoproteins, LDL; D014810:Vitamin E; D003300:Copper; D006861:Hydrogen Peroxide