Low density lipoprotein particles

Fig. 9-4). Very low-density lipoprotein particles are released into the circulation where they acquire apolipoprotein E and apolipoprotein C-II from HDL. Very-low density lipoprotein loses its triglyceride content through the interaction with LPL to form VLDL remnant and IDL. Intermediate-density lipoprotein can be cleared from the circulation by hepatic LDL receptors or further converted to LDL (by further depletion of triglycerides) through the action of hepatic lipases (HL). Approximately 50% of IDL is converted to LDL. Low-density lipoprotein particles are cleared from the circulation primarily by hepatic LDL receptors by interaction with apolipoprotein B-100. They can also be taken up by extra-hepatic tissues or enter the arterial wall, contributing to atherogenesis.4,6... 

Helisten H, Hockerstedt A, Wahala K et al. Accumulation of high-density lipoprotein-derived estradiol-17(3 fatty acid esters in low-density lipoprotein particles. J. Clin. Endocrinol Metab. 86, 1294-1300, 2001. 

In blood, lipids exist as lipoprotein particles, the main function of which is to transport lipids to and from various tissues and organs of the body. There is considerable interest in blood lipoproteins from the viewpoint of human health, especially obesity and cardiovascular diseases. Lipoproteins are classified into four groups on the basis of density, which is essentially a function of their triglyceride content, i.e. chylomicrons, very low density lipoprotein particles (VLDL), low density lipoprotein (LDL) particles and high density lipoprotein (HDL) particles, containing c. 98, 90, 77 and 45% total lipid, respectively (Figure 3.11). 

I Liver secretes nascent TG-rich very-low-density lipoprotein particles. 

Lamarche, B., Tchemof, A., Moorjani, S., Cantin, B., Dagenais, G. R., Lupien, P. J., and Despres, J. P. (1997). Small, dense low-density lipoprotein particles as a predictor of the risk of ischemic heart disease in men. Prospective results from the Quebec Cardiovascular Study. Circulation 95, 69-75. 

Superko, H.R. and Krauss, R.M. 2000. Garlic powder, effect on plasma lipids, postprandial lipemia, low-density lipoprotein particle size, high-density lipoprotein subclass distribution and lipoprotein(a). J. Am. Coll. Cardiol. 35, 321-326. 

High serum levels of cholesterol cause disease and death by contributing to the formation of atherosclerotic plaques in arteries throughout the body. This excess cholesterol is present in the form of the low density lipoprotein particle, so-called "bad cholesterol. "The ratio of cholesterol in the form of high density lipoprotein, sometimes referred to as "good cholesterol," to that in the form of LDL can be used to evaluate susceptibility to the development of heart disease. For a healthy person, the LDL/HDL ratio is 3.5. 

Stampfer, M. J., Krauss, R. M., Ma, J., Blanche, R, Holl, L. G., Sacks, E, and Hennekens, C. H. (1996). A prospective study of triglyceride level, low-density lipoprotein particle diameter, and risk of myocardial infarction. JAMA 276, 882-888. 

Lamarche B, Tchernof A, Mauriege P, Cantin B, Dagenais GR, Lupien PJ, Despres JP. Fasting insulin and apolipoprotein B levels and low-density lipoprotein particle size as risk factors for ischemic heart disease. JAMA 1998 279 1955-61. 

High serum levels of cholesterol cause disease and death by contributing to the formation of atherosclerotic plaques in arteries throughout the body. This excess cholesterol is present in the form of the low-density lipoprotein particle, so-called bad cholesterol. 

Oorni, K., Pentikainen, M.O., Ala-Korpela, M., Kovanen, P.T., Aggregation, fusion, and vesicle formation of modified low density lipoprotein particles molecular mechanisms and effects on matrix interactions, J LipidRes, 41 (2000) 1703-1714... 

Plasma PAF-AH is unique in that it is primarily associated with circulating high-density and low-density lipoprotein particles and rapidly transfers between these particles (D.M. Stafforini, 1987). The cDNA for this enzyme encodes a 44-kDa secretory protein... 

Fig. 1. Simplified schematic summary of the essential pathways for receptor-mediated human lipoprotein metabolism. The liver is the crossing point between the exogenous pathway (left-hand side), which deals with dietary lipids, and the endogenous pathway (right-hand side) that starts with the hepatic synthesis of VLDL. The endogenous metabolic branch starts with the production of chylomicrons (CM) in the intestine, which are converted to chylomicron remnants (CMR). Very-low-density lipoprotein particles (VLDL) are lipolyzed to LDL particles, which bind to the LDL receptor. IDL, intermediate-density lipoproteins LDL, low-density lipoproteins HDL, high-density lipoproteins LCAT, lecithinxholesterol acyltransferase CETP, cholesteryl ester transfer protein A, LDL receptor-related protein (LRPl) and W, LDL receptor. Lipolysis denotes lipoprotein lipase-catalyzed triacylglycerol lipolysis in the capillary bed.

The hydrophobic, water-insoluble cholesterol is transported in blood to cells predominantly as part of high density and low density lipoprotein particles (HDLs and LDLs, respectively). LDLs transport cholesterol to ex-trahepatic tissues. The LDL particles bind to LDL receptors on the cell... 

Dart, A.M., Martin, J.L., and Kay, S. 2002. Association between past infection with Chlamydia pneumoniae and body mass index, low-density lipoprotein particle size and fasting insulin. Int. J. Obes. Relat. Metab. Disord. 26, 464-468. 

Dreon DM, Femstrom HA, Campos H, Blanche R Williams PT, and Krauss RM, Change in dietary saturated fat intake is correlated with change in mass of large low-density-lipoprotein particles in men. Am J Clin Nutr, May 1998 67(5) 828-836. 

Liu, M., McNeal, C.J., and Macfarlane,R.D. Charge density profiling ofcirculating human low-density lipoprotein particles by capillary zone electrophoresis. Electrophoresis, 25, 2985, 2004. 

Sorensen, N.S., Marckmann, P., Hoy, C.E., van Duyvenvo-orde, W., and Prince, H.M. (1998) Effect of Fish-Oil-Enriched Margarine on Plasma Lipids, Low-Density-Lipoprotein Particle Composition, Size, and Susceptibility to Oxidation, Am. J. Clin. Nutr. 68, 235-241. 

Campos, H., Genest J.J. Jr, Blijlevens E. et al. Low density lipoprotein particle size and... 

Koren E, Alaupovic P, Lee DM, Dashti N, Kloer HU, Wen G (1987) Selective isolation of human plasma low-density lipoprotein particles containing apohpoproteins B and E by use of a monoclonal antibody to apolipoprotein B. Biochemistry 26 2734-2746... 

Oorni K, Pentikainen MO, Annila A and Kovanen PT. Oxidation of low density lipoprotein particles decreases their ability to bind to human aortic proteoglycans. Dependence on oxidative modification of the lysine residues. J Biol Chem 272 21303-11, 1997. 

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