Triglycerides metabolism lipids

Kashyap ML, Srivastava LS, Hynd BA, Perisutti G, Brady DW, Gartside P, Glueck CJ (1978) The role of high density lipoprotein apolipoprotein C-II in triglyceride metabolism. Lipids 13 933-942... 

Binnert, C., Laville, M., Pachiaudi, C., Rigalleau, V. and Beylot, M. (1995) Use of gas chromatography isotope ratio mass spectrometry to study triglyceride metabolism in humans. Lipids 30, 869 873. 

In normal lipid metabolism, lipids in the diet are converted to triglycerides, which are used in muscle and adipose tissue. Cholesterol is used for the synthesis of steroid hormones and bile acids and by all cells as part of the cell membrane. 

D, P, Katz and J. L. Knillle. The effect of medium and long chain triglyceride on human adipose tissue metabolism. Lipids. 22 4,35-441. 1987. 

Table 3. Correlation of bile acid and cholesterol synthesis with serum lipids and triglyceride metabolism in two families (n = 17) with familial hypertriglyceridemia...

B. Angelin, K. Einarsson and B. Leijd, Bile acids and triglyceride metabolism in man. m "Bile Acids and Lipids,"... 

Neptune, E. et al., Phospholipid and triglyceride metabolism of exercised rat diaphragm and the role of these lipids in fatty acid uptake and oxidation. J Lipid Res, 1 229, 1960. 

Lipid metabolism. Lipids are divided broadly into fats (triglycerides, esters of glycerol with three moles of fatty acids), sterols, and phospholipids such as phosphatidylcholine (lecithin) 4.38), All natural phospholipids have the L-3-glycerophosphoric structure. Each phospholipid is a family rather than a pure substance. The 2-position of lecithin is usually esterified by an imsaturated, and the i-position by a saturated, fatty acid of the Cjg or series. Double unsaturation in the 2-position is common (esteri-... 

Lipid-lowering diugs are diugs that affect the lipoprotein metabolism and that used in therapy to lower plasma lipids (cholesterol, triglycerides). The main classes of... 

PLTP is responsible for the majority of phospholipid transfer activity in human plasma. Specifically, it transfers surface phospholipids from VLDL to HDL upon lipolysis of triglycerides present in VLDL. The exact mechanism by which PLTP exerts its activity is yet unknown. The best indications for an important role in lipid metabolism have been gained from knockout experiments in mice, which show severe reduction of plasma levels of HDL-C and apoA-I. This is most likely the result of increased catabolism of HDL particles that are small in size as a result of phospholipid depletion. In addition to the maintenance of normal plasma HDL-C and apoA-I concentration, PLTP is also involved in a process called HDL conversion. Shortly summarized, this cascade of processes leads to fusion of HDL... 

Lipoprotein metabolism is the process by which hydrophobic lipids, namely triglycerides and cholesterol, are transported within the interstitial fluid and plasma. It includes the transport of energy in the form of triglycerides from intestine and liver to muscles and adipose, as well as the transport of cholesterol both from intestine and liver to peripheral tissues, as well as from peripheral tissues back to the liver. 

Metformin also has been shown to produce beneficial effects on serum lipid levels and thus has become a first-line agent for type 2 DM patients with metabolic syndrome. Triglyceride and low-density lipoprotein (LDL) cholesterol levels often are reduced by 8% to 15%, whereas high-density lipoprotein (HDL) cholesterol improves by approximately 2%. A modest weight loss of 2 to 3 kg (4.4—6.6 lb) also has been reported with metformin therapy. Metformin often is used in combination with a sulfonylurea or a thiazolidinedione for synergistic effects. 

Experiments with monkeys given intramuscular injections of a mineral oil emulsion with [l-14C] -hexa-decane tracer provide data illustrating that absorbed C-16 hydrocarbon (a major component of liquid petrolatum) is slowly metabolized to various classes of lipids (Bollinger 1970). Two days after injection, substantial portions of the radioactivity recovered in liver (30%), fat (42%), kidney (74%), spleen (81%), and ovary (90%) were unmetabolized -hexadecane. The remainder of the radioactivity was found as phospholipids, free fatty acids, triglycerides, and sterol esters. Essentially no radioactivity was found in the water-soluble or residue fractions. One or three months after injection, radioactivity still was detected only in the fat-soluble fractions of the various organs, but 80-98% of the detected radioactivity was found in non-hydrocarbon lipids. 

Lipoproteins. A lipoprotein is an endogenous macromolecule consisting of an inner apolar core of cholesteryl esters and triglycerides surrounded by a monolayer of phospholipid embedded with cholesterol and apoproteins. The functions of lipoproteins are to transport lipids and to mediate lipid metabolism. There are four main types of lipoproteins (classified based on their flotation rates in salt solutions) chylomicrons, very-low-density lipoprotein (VLDL), low-density lipoprotein (LDL), and high-density lipoprotein (HDL). These differ in size, molecular weight, and density and have different lipid, protein, and apoprotein compositions (Table 11). The apoproteins are important determinants in the metabolism of lipoproteins—they serve as ligands for lipoprotein receptors and as mediators in lipoproteins interconversion by enzymes. 

Interestingly, it has been shown that supplementation of greenfinches with lutein and zeaxanthin at a ratio of 20 1 increases plasma levels of triglycerides and bird body mass (Horak et al., 2006). These data suggest that xanthophylls may affect lipid metabolism. 

The neurohormonal control of lipid metabolism chiefly affects the mobilization and synthesis of triglycerides in the fat tissue. The lipolysis in tissues is dependent upon the activity of triglyceride lipase. All the regulators that favour the conversion of the inactive (nonphosphorylated) lipase to the active (phosphoiylated) one, stimulate the lipolysis and the release of fatty acids into the blood. Adrenalin... 

Most commonly, the lipid metabolism pathology is manifest as hyperlipemia (elevated concentration of lipids in blood) and tissue lipidoses (excessive lipid de-position in tissues). Normally, the lipid contents in the blood plasma are total lipids, 4-8 g/litre triglycerides, 0.5-2.1 mmol/litre total phospholipids, 2.0-3.5 mmol/litre total cholesterol, 4.0-8.0 mmol/litre (esterified cholesterol accounts for 2/3 of total cholesterol). 

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