Lipoprotein and cholesterol metabolism in the brain involves metabolic pathways that are regulated independently of those in the peripheral circulation and tissues. The blood–brain barrier (BBB) restricts plasma lipids, including cholesterol and plasma lipoproteins, from entering or leaving the central nervous system (CNS). In the CNS, cholesterol is synthesized by astrocytes, oligodendrocytes,...

Lipoprotein and cholesterol metabolism in the brain involves metabolic pathways that are regulated independently of those in the peripheral circulation and tissues. The blood–brain barrier (BBB) restricts plasma lipids, including cholesterol and plasma lipoproteins, from entering or leaving the central nervous system (CNS). In the CNS, cholesterol is synthesized by astrocytes, oligodendrocytes,...

We compared the results obtained by a micromethod for the determination of plasma lipoprotein cholesterol, in which electrophoresis is used to separate the lipoprotein fractions (beta-, pre-beta-, and alpha-lipoproteins), with those determinations with ultracentrifugation (low-density, very-low-density, and high-density lipoproteins). Precision of determination (coefficient of variation, CV, %)...

The role of the human intestine has been explored as a site of synthesis of apoA-IV, a major apoprotein of human intestinal triglyceride-rich lipoproteins. Intestinal biopsies were performed on normal volunteers while fasting and after lipid ingestion. Indirect immunofluorescence demonstrated a marked increase in immunofluorescence for apoA-IV during lipid absorption consistent with an increase...

The feeding of cholesterol to rats resulted in marked alterations in the type and distribution of the plasma lipoproteins and their apoproteins. The hyperlipoproteinemia was characterized by an increase in the d < 1.006 lipoproteins (B-VLDL and VLDL), an increase in the intermediate and low density lipoproteins (LDL), and the appearance of HDL(c). Associated with these lipoproteins was a promin...

Animal cholesterol synthesis shows a marked diurnal variation, a phenomenon, at the moment, not known to occur in man. Since cholesterol precursors in serum reflect overall cholesterol synthesis in many conditions, a 24-hr profile of squalene and methyl sterols was studied in plasma lipoproteins in order to demonstrate whether these cholesterol precursors could exhibit a diurnal cycling in heal...

In a subendothelial space of atherosclerotic arteries, apolipoprotein B-containing lipoproteins are accumulated and oxidized, and the oxidized lipoproteins promote macrophage foam cell formation. Therefore, the analysis of vitamin E, a major antioxidant in lipoproteins, is important for understanding atherosclerotic pathogenesis. A new method for the automated measurement of vitamin-E (γ- and α...

The present study demonstrates very high levels of plasma lipids and high density lipoprotein (HDL) apolipoproteins (apoA-I and apoE) in female Nagase analbuminemic rats (NAR) fed a semi-synthetic diet in order to further increase the hyperlipidemia present in this strain. Plasma apoB-containing lipoproteins (very low, intermediate, and low density lipoproteins) were also elevated in NAR. Plasm...

Natural abundance 13C NMR spectra of high density, low density, and very low density lipoproteins isolated from human plasma have been recorded and assigned, and the spin lattice relaxation times (T1) of some well resolved resonances have been determined. The laC NMR spectra reflect differences in protein-lipid ratios and in lipid composition between the three classes of lipoproteins. All three...