Headspace gas chromatography to determine human low density lipoprotein oxidation.
We previously described a rapid headspace gas chromatographic method for the determination of hexanal, an important decomposition product of n-6 polyunsaturated fatty acid (PUFA) peroxidation in rat liver samples and human red blood cell membranes. This method was applied to the measurement of Cu2+ catalyzed-oxidation of freshly prepared human low density lipoproteins (LDL) from 10 healthy adult volunteers. A twofold variation in oxidative susceptibility was found by this assay for hexanal and other volatiles. Hexanal values correlated significantly (P < 0.05) with total polyunsaturated fatty acid (PUFA), 18:2 and n-6 PUFA contents of LDL; but poorly with 20:4 and with vitamin E. Therefore, in addition to alpha-tocopherol, other endogenous antioxidants and factors may contribute to LDL's resistance to oxidation. This simple, rapid and sensitive method for oxidative susceptibility provides a useful component in the analysis of the prooxidant/antioxidant status of biological samples. The method is used routinely in our laboratories to determine specific peroxidation products of n-6 and n-3 PUFA.
Frankel
E N
EN
Department of Food Science and Technology, University of California, Davis 95616.
German
J B
JB
Davis
P A
PA
D000328:Adult; D000447:Aldehydes / Q000032:analysis*; D000975:Antioxidants; D002849:Chromatography, Gas / Q000379:methods; D003300:Copper / Q000737:chemistry; D005231:Fatty Acids, Unsaturated / Q000737:chemistry; D006801:Humans; D015227:Lipid Peroxidation; D008077:Lipoproteins, LDL / Q000737:chemistry*; D010084:Oxidation-Reduction; D010420:Pentanes / Q000032:analysis
D000447:Aldehydes; D000975:Antioxidants; D005231:Fatty Acids, Unsaturated; D008077:Lipoproteins, LDL; D010420:Pentanes; C033353:pentane; D003300:Copper; C010463:n-hexanal; C005556:propionaldehyde; C046012:pentanal