The issue of whether chylomicron remnants are atherogenic has been much debated. A number of reports, which will be discussed later, point to a relationship between impaired metabolism of postprandial triacylglycerol-rich lipoproteins and the presence of coronary artery disease (CAD). For the purpose of standardization, the levels of plasma lipids and lipoproteins are generally measured in the ...

Because lipoproteins containing apolipoprotein A (ApoA-I + ApoA-II) or apolipoprotein B (ApoB) seem to exert opposite effects as risk factors for coronary heart disease, we decided to determine the separability of these two major plasma lipoproteins by procedures originally designed to separate high-density from low- and very-low-density lipoproteins. The presumably ApoB-free lipoproteins isola...

This study was designed to further ascertain the presence in plasma of lipoprotein lipase (LPL) bound to circulating lipoproteins. Lipoprotein lipase mass and activity values in preheparin plasma from 20 volunteers were 69.8 +/- 6.6 ng.ml-1 and 1.54 +/- 0.15 mU.ml-1, respectively, and no significant correlation between mass and activity was observed. Fifteen min after heparin injection, LPL mas...

We have studied the interaction of small unilamellar liposomes containing zinc(II)-phthalocyanine (Zn-Pc) with human plasma lipoproteins. High-, low- and very low-density lipoproteins (HDL, LDL and VLDL), were purified from plasma and combined in amounts reflecting their natural abundance in plasma. After short periods of incubation at 37 degrees C, the bulk of Zn-Pc was incorporated into HDL a...

The aqueous solubilities of most lipids in lipoproteins are so low that their transfer between lipoproteins and cell membranes depends on random (collision) or specific (receptor-mediated) physical interaction between donor and acceptor interfaces, or the activity of transfer proteins which serve to increase the solubility of lipids in the aqueous phase (1). However, the solubility of cholester...

The prevention of atherosclerosis by apolipoprotein E (apoE) is generally attributed to the removal of plasma lipoprotein remnant particles. We developed transgenic apoE-knockout mice expressing apoE specifically in the adrenal gland and found that only 3% of the wild-type plasma level of apoE was sufficient to normalize plasma cholesterol levels in the apoE-deficient mouse. As expected, mice e...

Monocytes are recruited from the circulation into the subendothelial space where they differentiate into mature macrophages and internalize modified lipoproteins to become lipid-laden foam cells. The accumulation of monocytes is mediated by the interaction of locally produced chemoattractant protein-1 (MCP-1) with its receptor CCR2. The objective of the present study is to demonstrate the diffe...

The structure and function of plasma lipoproteins have received increasing attention in the past few years. The recognition of the importance of the protein moiety for the structural stability and metabolism of these conjugated macromolecules has stimulated this field of research and has emphasized the careful characterization of the apo-lipoproteins for a better understanding of lipid transpor...