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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1991-6-19
pubmed:abstractText
The oxidative modification of low density lipoprotein (LDL) may provide a crucial link between plasma LDL and the atherosclerotic lesion. The studies presented herein define time-dependent modifications of LDL constituents caused by CuSO4-catalyzed oxidation. Measurement of the cholesterol content of oxidized LDL by the cholesterol esterase-oxidase assay was found to be inaccurate. The enzymatic assay detected oxysterols as well as cholesterol and thus substantially overestimated the actual cholesterol content. Alteration of electrophoretic mobility and conversion of sterols into oxysterols increased in a parallel, time-dependent manner. Lipid peroxidation, judged by the thiobarbituric acid-reacting substances assay, increased early to maximal values but was not linearly related to either electrophoretic mobility or to oxysterol formation. Neither electrophoretic mobility nor oxysterol formation varied much between repeated oxidative modifications of any given LDL preparation but varied markedly among LDLs from different normolipidemic individuals, suggesting that LDL particles contain some factor conferring susceptibility or resistance to oxidation. Indeed, LDL preparations from different individuals have varying susceptibilities to oxidative modification as evidenced by the three indexes used. The major oxysterol generated was 7-ketocholesterol. Macrophage modification of LDL also resulted in the generation of oxysterols. Thus, measurement of oxysterols may afford an additional index of the oxidative modification of LDL. Since incubation of macrophages with oxidized LDL but not native LDL resulted in the accumulation of oxysterols, this could account for some of the toxic and metabolic effects of oxidized LDL on cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1049-8834
pubmed:author
pubmed:issnType
Print
pubmed:volume
11
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
482-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:articleTitle
Varying susceptibility of different low density lipoproteins to oxidative modification.
pubmed:affiliation
Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas 75235.
pubmed:publicationType
Journal Article