The Chylomicron: Relationship to Atherosclerosis
نویسندگان
چکیده
The B-containing lipoproteins are the transporters of cholesterol, and the evidence suggests that the apo B48-containing postprandial chylomicron particles and the triglyceride-rich very low density lipoprotein (VLDL) particles play an important part in the development of the plaque both directly and indirectly by their impact on LDL composition. The ratio of dietary to synthesised cholesterol is variable but tightly regulated: hence intervention with diet at best reduces serum cholesterol by <20% andusually <10%. Statins are the mainstay of cholesterol reduction therapy, but they increase cholesterol absorption, an example of the relationship between synthesis and absorption. Inhibition of cholesterol absorption with Ezetimibe, an inhibitor of Niemann Pick C1-like 1 (NPC1-L1), the major regulator of cholesterol absorption, increases cholesterol synthesis and hence the value of adding an inhibitor of cholesterol absorption to an inhibitor of cholesterol synthesis. Apo B48, the structural protein of the chylomicron particle, is synthesised in abundance so that the release of these particles is dependent on the amount of cholesterol and triglyceride available in the intestine. This paper will discuss cholesterol absorption and synthesis, chylomicron formation, and the effect of postprandial lipoproteins on factors involved in atherosclerosis.
منابع مشابه
Chylomicron metabolism.
Chylomicrons are the 'orphans' of the lipoprotein family. Difficulty of measurement has impeded understanding of their metabolism. Plasma concentrations of chylomicrons and chylomicron remnants give no insight into the magnitude of substrate flux through these pathways. A defect in clearance of chylomicron remnants is probably an indication of a more generalized defect in lipoprotein metabolism...
متن کامل[Frontiers in Bioscience 6, d332-354, March 1, 2001] 332 POSTPRANDIAL LIPOPROTEINS AND ATHEROSCLEROSIS
1. Abstract 2. Introduction 3. Chylomicrons and chylomicron remnants 4. Methods to determine the rate of removal of chylomicrons and remnants from the plasma 4.1. Intravenous bolus injection 4.2 Oral fat test meal (fat intolerance test) 5. The role of the liver 5.1. Receptors for chylomicron remnants 5.1.1. LDL receptor 5.1.2. LDL receptor-related-protein/alpha-2-macroglobulin receptor 5.1.3. H...
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Chylomicron remnants have been suggested to be involved in the development of atherosclerosis. To investigate the mechanisms of chylomicron remnant-induced atherosclerosis, we prepared cholesterol (Chol)-containing emulsion particles as models for chylomicron remnants. Chol markedly increased the apolipoprotein E (apoE) binding maximum of emulsions without changing the binding affinity and ther...
متن کاملSmall liver fenestrae may explain the susceptibility of rabbits to atherosclerosis.
Rabbits fed cholesterol rapidly develop high serum cholesterol levels which lead to the development of atherosclerosis. This is related to the retention of cholesterol-rich chylomicron remnants in the circulation. In most animals, such as rats, chylomicron remnants are rapidly removed from the circulation by the liver. The first barrier to this removal is the fenestrated endothelium of liver si...
متن کاملPostprandial enrichment of remnant lipoproteins with apoC-I in healthy normolipidemic men with early asymptomatic atherosclerosis.
OBJECTIVES Recently, we reported that exaggerated postprandial triglyceridemia in normolipidemic patients with coronary artery disease is associated with enrichment of remnant lipoproteins with apolipoprotein C-I (apoC-I). In this study, the number and composition of chylomicron remnants and very low density lipoproteins (VLDLs) were examined in 30 asymptomatic normolipidemic 50-year-old men wi...
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عنوان ژورنال:
دوره 2012 شماره
صفحات -
تاریخ انتشار 2012