Composition and immunoreactivity of serum low density lipoproteins (LDL) before and after LDL-apheresis on dextran sulfate-cellulose columns.
The changes in low density lipoprotein (LDL) composition and immunoreactivity occurring after LDL-apheresis on dextran sulfate-cellulose columns (DSC) were investigated in 4 hypercholesterolemic patients. After apheretic treatment, serum levels of total cholesterol, triglycerides and apolipoprotein B (apo B) were decreased by 63, 80 and 65%, respectively, whereas the high density lipoprotein (HDL)-cholesterol remained unchanged. At the end of apheresis, LDL contained less triglycerides, more phospholipids and apo E and the ratio of LDL core lipid components, cholesteryl esters and triglycerides, to LDL surface lipid components, unesterified cholesterol and phospholipids was significantly lower. The post-apheretic LDL were characterized by the presence of subfractions slightly larger than those observed in the pre-apheretic LDL. The modifications of the composition and size of LDL after apheresis were accompanied by a relative increase in the immunoreactivity of 4G3 epitope, an apo B epitope located near the LDL-receptor binding site, with no change in the affinity of 1D1, an apo B epitope located in the amino-terminal region of the molecule. The changes in LDL composition, size and immunoreactivity following apheresis, suggest that postapheresis LDL could contain newly synthesized LDL, different from mature LDL. Thus, LDL-apheresis treatment could provide the opportunity to study the structural change of LDL during intravascular metabolism.
Gandjini
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Laboratoire de Biochimie des Lipoprotéines, Faculté de Médecine, Dijon, France.
Gambert
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Athias
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Mousson
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Rifle
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Lallemant
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D000911:Antibodies, Monoclonal; D000925:Anticoagulants / Q000494:pharmacology*; D001055:Apolipoproteins B / Q000097:blood / Q000276:immunology; D001781:Blood Component Removal; D002482:Cellulose; D016264:Dextran Sulfate / Q000494:pharmacology*; D005260:Female; D006801:Humans; D006937:Hypercholesterolemia / Q000097:blood* / Q000276:immunology / Q000628:therapy; D008055:Lipids / Q000097:blood; D008077:Lipoproteins, LDL / Q000097:blood* / Q000737:chemistry / Q000187:drug effects / Q000276:immunology; D008297:Male; D008875:Middle Aged