Biliary lipids, composed of bile acids, cholesterol, and phosphatidylcholine, are a major source of luminal lipid in the small intestine. In the present study in a newborn swine intestinal epithelial cell line (IPEC-1), taurocholate and phosphatidylcholine were found to have no effect on apolipoprotein B (apo B) secretion but did significantly increase the basolateral secretion of apo A-I. This...

The C apolipoproteins are normally transferred to high density lipoproteins (HDL) after lipolysis of very low density lipoprotein (VLDL) triglyceride. In previous studies, a loss of plasma C apolipoproteins was documented after heparin-induced lipolysis in hypertriglyceridemic subjects. The present studies were designed to determine if this decline in plasma C apolipoproteins was due to their c...

Because of suggestions that thyroid hormones modulate serum lipoprotein(a) [Lp(a)] concentration, we evaluated prospectively the serial changes of serum Lp(a), measured as apolipoprotein(a) [apo(a)], and other lipoproteins in 40 subjects with hyperthyroidism treated with radioactive iodine (RAI) therapy. Hyperthyroid patients had lower (P < 0.001) concentrations of apo(a), total cholesterol (TC...

We have investigated the intracellular distribution of apolipoprotein B (apo B) in rabbit liver by immunoblotting, radioimmunoassay (r.i.a.) and enzyme-linked immunoassay (e.l.i.s.a.). Apo B100 was detected in total microsomes, rough microsomes, smooth microsomes, trans-enriched Golgi and cis-enriched Golgi and membrane and cisternal-content subfractions prepared from these fractions. There was...

The ability of low-density lipoprotein (LDL) to inhibit the procoagulant activity of tissue factor is mediated by a direct protein-protein interaction involving apolipoprotein (apo) B-100. A lysine-rich sequence within apo B-100 (residues 3121-3217), which we have termed lysine-rich apo B-100-derived (KRAD)-98 peptide, may be responsible for its activity. Within this region, residues 3147-3160 ...

The aim of the present study was to investigate cholesterol absorption and cholesterol and bile acid synthesis and relate these values of kinetics of low-density lipoprotein (LDL) apoprotein (apo) B in 50- and 75-year-old men to find out why and by which mechanism serum cholesterol level decreases with advancing age under normal home-living conditions. The daily calorie, fat, and cholesterol in...

We describe a new method for the direct measurement of LDL-apolipoprotein (apo) B by using a commercial kit that isolates LDL by immunoseparation. We evaluated immunoseparation of LDL for apo B and cholesterol measurement in 46 dyslipidemic patients with LDL-cholesterol (LDL-C) between 1.5 and 8.2 mmol/L, 11 of whom had plasma triglyceride (TG) concentrations >4.0 mmol/L. There was a reasonable...

Familial defective apolipoprotein (apo) B-100 (FDB), a condition that may give rise to hypercholesterolemia, is caused by mutations around codon 3500 of the apo B gene. We have compared the ability of three molecular-scanning techniques, heteroduplex analysis, single-strand conformation polymorphism (SSCP) analysis, and denaturing gradient gel electrophoresis (DGGE), to detect these mutations i...

It has recently been suggested that a substitution of glutamine for arginine at residue 3500 of apolipoprotein (apo) B-100 causes familial defective apo B-100 (FDB), an autosomal, dominantly inherited disorder, which leads to increased serum cholesterol levels. From a sample of 243 patients from Munich with type IIa hyperlipoproteinemia (HL), we have identified eight individuals with the apo B-...

The kinetics of apolipoprotein (apo) B-100 in particles containing apo E (B,E particles) or lacking apo E (B particles) were studied in Watanabe heritable hyperlipidemic (WHHL) rabbits deficient in low density lipoprotein (LDL) receptors, and compared with those of normal rabbits after injection of radioiodinated very low density lipoproteins (VLDL), intermediate density lipoproteins (IDL), and...