sepharose and Hypercholesterolemia

Low levels of high-density lipoproteins (HDLs) may constitute an independent risk factor that may be as important as elevated low-density lipoproteins (LDLs) in coronary artery disease (CAD). Concentrations and distributions of lipids, apolipoprotein (apo) B, and apoA-I in the plasma and lipoprotein subfractions of two groups of swine, one with familial hypercholesterolemia (FHC) and the other with diet-induced hypercholesterolemia (DHC), were examined. Normolipidemic (NL) animals served as controls. All pigs carried the Lpb5 apoB mutation, which is known to influence the formation of atherosclerotic lesions. Mean concentrations of serum total cholesterol in NL, DHC, and FHC were 80.0 +/- 9.3, 774.3 +/- 54.5, and 316.5 +/- 36.1 mg/dL, respectively; HDL cholesterol (HDL-C), 33.5 +/- 1.9, 137.0 +/- 9.9, and 22.3 +/- 2.2 mg/dL; triglycerides, 33.0 +/- 16.3, 40.3 +/- 11.7, and 56.8 +/- 7.2 mg/dL; apoB, 35.7 +/- 3.1, 142.0 +/- 4.8, and 169.3 +/- 13.9 mg/dL; and apoA-I, 62.4 +/- 9.3, 170.9 +/- 6.9, and 42.6 +/- 4.8 mg/dL. The distributions of total cholesterol, apoB, and apoA-I in plasma lipoprotein subfractions were also examined. Compared with NL, FHC had fourfold and 4.7-fold increases in total cholesterol and apoB, respectively, distributed in the lower densities (d < 1.043 g/mL), and low HDL-C and apoA-I levels, resulting in a high total cholesterol/HDL-C ratio (14.4:1) and elevated triglyceride levels. DHC was characterized by 10-fold and fourfold increases in total cholesterol and apoB, respectively, resulting in an LDL particle highly enriched in cholesterol, a fourfold increase of HDL-C, an almost threefold increase in apoA-I, and a normal triglyceride level.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Apolipoprotein A-I; Apolipoproteins B; Cholesterol; Diet; Disease Models, Animal; Electrophoresis, Polyacrylamide Gel; Gels; Hypercholesterolemia; Hyperlipoproteinemia Type II; Immunoelectrophoresis; Lipids; Lipoproteins; Male; Sepharose; Sodium Dodecyl Sulfate; Swine

Rat serum phosphorylcholine binding protein was earlier shown to bind lipoproteins containing apoproteins B and E from human very low and low density lipoproteins. The present studies were undertaken to show the effectiveness of rat serum phosphorylcholine-binding protein immobilized on Sepharose affinity column to remove apoprotein-B-containing lipoproteins from normal and hypercholesterolemic rabbit plasma, when used in a plasmapheresis system. The maximum in vitro binding of very low and low density lipoproteins from hypercholesterolemic rabbit plasma to the affinity adsorbent was Ca2+ dependent, and the cholesterol bound to the column at the optimum calcium concentration (2.5 mM) was 21% of the total plasma cholesterol applied. The in vivo binding of total cholesterol from normal and hypercholesterolemic rabbit plasma during plasmapheresis ranged from 0.22 to 7.7%. Total mass of cholesterol bound ranged from 3.86 and 27.52 mg at plasma cholesterol concentrations 13.8 and 282 mg/dL, respectively. Most (greater than 95%) of the bound cholesterol was associated with very low and low density lipoproteins. These studies show the ability of immobilized rat serum phosphorylcholine-binding protein to lower the atherogenic apoprotein-B-containing lipoproteins from plasma of hypercholesterolemic rabbits.

Topics: Adsorption; Animals; Apolipoproteins B; Calcium; Carrier Proteins; Hypercholesterolemia; Male; Phosphorylcholine; Plasmapheresis; Rabbits; Rats; Sepharose

A reproducible and quantitative subfractionation of human high density lipoproteins (HDL) by heparin-Sepharose affinity chromatography has been developed. Two elution methods (A and B) were used to subfractionate HDL(2) (d 1.063-1.125 g/ml) or total HDL (d 1.063-1.21 g/ml). Method A separated HDL(2) into three subclasses, each with distinct chemical properties and in vitro metabolic characteristics. The first subclass, referred to as HDL(2)-without E, passed through the affinity column unretarded and represented approximately 85% of the HDL(2) lipoprotein protein. HDL(2)-without E contained the A-I, A-II, and C apoproteins which characterize typical HDL. The second subclass eluted from the column (7-10% of the protein) contained, in addition to the A-I and A-II apoproteins, the E and (E-A-II) apoproteins, and was designated as HDL(2)-with E. The B apoprotein was the major protein component of the third subclass eluted from the column (beta lipoproteins). The beta subclass accounted for approximately 3-8% of the HDL(2) protein and was similar to Lp(a) in composition and size. Method B further subdivided the beta subclass into two fractions (beta(1) and beta(2)) with slightly different electrophoretic mobilities. The various heparin-Sepharose subclasses were further characterized by their ability to compete with (125)I-labeled low density lipoproteins (LDL) for binding to cell surface receptor sites of fibroblasts. By virtue of the presence of the E apoprotein, HDL(2)-with E competed effectively with (125)I-labeled LDL for binding to the cell surface receptors, whereas HDL(2)-without E were ineffective in competing with LDL. The beta subclass possessed binding capability similar to that of LDL. Subfractionation of HDL by heparin-Sepharose affinity column chromatography provides an attractive alternative to methods based solely on ultracentrifugation, in that it subfractionates HDL into subclasses with differing apoprotein contents that impart distinct metabolic characteristics to each class.-Weisgraber, K. H., and R. W. Mahley. Subfractionation of human high density lipoproteins by heparin-Sepharose affinity chromatography.

Topics: Apolipoproteins; Chromatography, Affinity; Heparin; Humans; Hypercholesterolemia; Lipoproteins, HDL; Particle Size; Sepharose

Reduction of plasma-cholesterol by the removal of low-density lipoproteins (L.D.L.) in an extracorporeal system is described as a possible approach in the treatment of familial hypercholesterolaemia. L.D.L. were removed from the blood by their interaction with heparin linked to agarose beads in the presence of calcium ions. Plasma-L.D.L. was markedly decreased in two patients with heterozygous familial hypercholesterolaemia. The technique is specific for the removal of L.D.L., as the concentration of high-density lipoproteins was not affected. The treatment was well tolerated by all three subjects (i.e., two hypercholesterolaemic patients and a normal volunteer), and there were no undesirable effects. Several haematological parameters, clinical-chemistry tests, including serum enzymes, and immunoelectrophoresis of plasma proteins were all unaffected by the treatment.

Topics: Calcium; Cholesterol; Chromatography, Affinity; Extracorporeal Circulation; Follow-Up Studies; Heparin; Heterozygote; Humans; Hypercholesterolemia; Hyperlipidemias; Lipoproteins, HDL; Lipoproteins, LDL; Male; Middle Aged; Plasmapheresis; Sepharose