A class of lipoproteins that carry dietary CHOLESTEROL and TRIGLYCERIDES from the SMALL INTESTINE to the tissues. Their density (0.93-1.006 g/ml) is the same as that of VERY-LOW-DENSITY LIPOPROTEINS.
The interstitial fluid that is in the LYMPHATIC SYSTEM.
An opaque, milky-white fluid consisting mainly of emulsified fats that passes through the lacteals of the small intestines into the lymphatic system.
Triglycerides are the most common type of fat in the body, stored in fat cells and used as energy; they are measured in blood tests to assess heart disease risk, with high levels often resulting from dietary habits, obesity, physical inactivity, smoking, and alcohol consumption.
An enzyme of the hydrolase class that catalyzes the reaction of triacylglycerol and water to yield diacylglycerol and a fatty acid anion. The enzyme hydrolyzes triacylglycerols in chylomicrons, very-low-density lipoproteins, low-density lipoproteins, and diacylglycerols. It occurs on capillary endothelial surfaces, especially in mammary, muscle, and adipose tissue. Genetic deficiency of the enzyme causes familial hyperlipoproteinemia Type I. (Dorland, 27th ed) EC 3.1.1.34.
A 241-kDa protein synthesized only in the INTESTINES. It serves as a structural protein of CHYLOMICRONS. Its exclusive association with chylomicron particles provides an indicator of intestinally derived lipoproteins in circulation. Apo B-48 is a shortened form of apo B-100 and lacks the LDL-receptor region.
A class of lipoproteins of very light (0.93-1.006 g/ml) large size (30-80 nm) particles with a core composed mainly of TRIGLYCERIDES and a surface monolayer of PHOSPHOLIPIDS and CHOLESTEROL into which are imbedded the apolipoproteins B, E, and C. VLDL facilitates the transport of endogenously made triglycerides to extrahepatic tissues. As triglycerides and Apo C are removed, VLDL is converted to INTERMEDIATE-DENSITY LIPOPROTEINS, then to LOW-DENSITY LIPOPROTEINS from which cholesterol is delivered to the extrahepatic tissues.
Lipid-protein complexes involved in the transportation and metabolism of lipids in the body. They are spherical particles consisting of a hydrophobic core of TRIGLYCERIDES and CHOLESTEROL ESTERS surrounded by a layer of hydrophilic free CHOLESTEROL; PHOSPHOLIPIDS; and APOLIPOPROTEINS. Lipoproteins are classified by their varying buoyant density and sizes.
Protein components on the surface of LIPOPROTEINS. They form a layer surrounding the hydrophobic lipid core. There are several classes of apolipoproteins with each playing a different role in lipid transport and LIPID METABOLISM. These proteins are synthesized mainly in the LIVER and the INTESTINES.
Colloids formed by the combination of two immiscible liquids such as oil and water. Lipid-in-water emulsions are usually liquid, like milk or lotion. Water-in-lipid emulsions tend to be creams. The formation of emulsions may be aided by amphiphatic molecules that surround one component of the system to form MICELLES.
Fats present in food, especially in animal products such as meat, meat products, butter, ghee. They are present in lower amounts in nuts, seeds, and avocados.
Major structural proteins of triacylglycerol-rich LIPOPROTEINS. There are two forms, apolipoprotein B-100 and apolipoprotein B-48, both derived from a single gene. ApoB-100 expressed in the liver is found in low-density lipoproteins (LIPOPROTEINS, LDL; LIPOPROTEINS, VLDL). ApoB-48 expressed in the intestine is found in CHYLOMICRONS. They are important in the biosynthesis, transport, and metabolism of triacylglycerol-rich lipoproteins. Plasma Apo-B levels are high in atherosclerotic patients but non-detectable in ABETALIPOPROTEINEMIA.
The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.
The largest lymphatic vessel that passes through the chest and drains into the SUBCLAVIAN VEIN.
Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of CAROTENOIDS found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products.
Unctuous combustible substances that are liquid or easily liquefiable on warming, and are soluble in ether but insoluble in water. Such substances, depending on their origin, are classified as animal, mineral, or vegetable oils. Depending on their behavior on heating, they are volatile or fixed. (Dorland, 28th ed)
The time frame after a meal or FOOD INTAKE.
A group of apolipoproteins that can readily exchange among the various classes of lipoproteins (HDL; VLDL; CHYLOMICRONS). After lipolysis of TRIGLYCERIDES on VLDL and chylomicrons, Apo-C proteins are normally transferred to HDL. The subtypes can modulate remnant binding to receptors, LECITHIN CHOLESTEROL ACYLTRANSFERASE, or LIPOPROTEIN LIPASE.
A class of lipoproteins of small size (4-13 nm) and dense (greater than 1.063 g/ml) particles. HDL lipoproteins, synthesized in the liver without a lipid core, accumulate cholesterol esters from peripheral tissues and transport them to the liver for re-utilization or elimination from the body (the reverse cholesterol transport). Their major protein component is APOLIPOPROTEIN A-I. HDL also shuttle APOLIPOPROTEINS C and APOLIPOPROTEINS E to and from triglyceride-rich lipoproteins during their catabolism. HDL plasma level has been inversely correlated with the risk of cardiovascular diseases.
Fatty acid esters of cholesterol which constitute about two-thirds of the cholesterol in the plasma. The accumulation of cholesterol esters in the arterial intima is a characteristic feature of atherosclerosis.
The metabolic process of breaking down LIPIDS to release FREE FATTY ACIDS, the major oxidative fuel for the body. Lipolysis may involve dietary lipids in the DIGESTIVE TRACT, circulating lipids in the BLOOD, and stored lipids in the ADIPOSE TISSUE or the LIVER. A number of enzymes are involved in such lipid hydrolysis, such as LIPASE and LIPOPROTEIN LIPASE from various tissues.
Uptake of substances through the lining of the INTESTINES.
Structural proteins of the alpha-lipoproteins (HIGH DENSITY LIPOPROTEINS), including APOLIPOPROTEIN A-I and APOLIPOPROTEIN A-II. They can modulate the activity of LECITHIN CHOLESTEROL ACYLTRANSFERASE. These apolipoproteins are low in atherosclerotic patients. They are either absent or present in extremely low plasma concentration in TANGIER DISEASE.
(Z)-9-Octadecenoic acid 1,2,3-propanetriyl ester.
A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.
The protein components of a number of complexes, such as enzymes (APOENZYMES), ferritin (APOFERRITINS), or lipoproteins (APOLIPOPROTEINS).
A 9-kDa protein component of VERY-LOW-DENSITY LIPOPROTEINS. It contains a cofactor for LIPOPROTEIN LIPASE and activates several triacylglycerol lipases. The association of Apo C-II with plasma CHYLOMICRONS; VLDL, and HIGH-DENSITY LIPOPROTEINS is reversible and changes rapidly as a function of triglyceride metabolism. Clinically, Apo C-II deficiency is similar to lipoprotein lipase deficiency (HYPERLIPOPROTEINEMIA TYPE I) and is therefore called hyperlipoproteinemia type IB.
Cell surface proteins that bind lipoproteins with high affinity. Lipoprotein receptors in the liver and peripheral tissues mediate the regulation of plasma and cellular cholesterol metabolism and concentration. The receptors generally recognize the apolipoproteins of the lipoprotein complex, and binding is often a trigger for endocytosis.
A class of lipoproteins of small size (18-25 nm) and light (1.019-1.063 g/ml) particles with a core composed mainly of CHOLESTEROL ESTERS and smaller amounts of TRIGLYCERIDES. The surface monolayer consists mostly of PHOSPHOLIPIDS, a single copy of APOLIPOPROTEIN B-100, and free cholesterol molecules. The main LDL function is to transport cholesterol and cholesterol esters to extrahepatic tissues.
'Blood Protein Disorders' refer to conditions characterized by an abnormal amount, structure, or function of proteins present in the blood, including immunoglobulins, coagulation factors, complement components, and transport proteins, which can lead to various clinical manifestations such as immune dysfunction, bleeding disorders, or metabolic imbalances.
Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.
Centrifugation with a centrifuge that develops centrifugal fields of more than 100,000 times gravity. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The fatty portion of milk, separated as a soft yellowish solid when milk or cream is churned. It is processed for cooking and table use. (Random House Unabridged Dictionary, 2d ed)
Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)
An enzyme of the hydrolase class that catalyzes the reaction of triacylglycerol and water to yield diacylglycerol and a fatty acid anion. It is produced by glands on the tongue and by the pancreas and initiates the digestion of dietary fats. (From Dorland, 27th ed) EC 3.1.1.3.
A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)
A layer of the peritoneum which attaches the abdominal viscera to the ABDOMINAL WALL and conveys their blood vessels and nerves.
Absorptive cells in the lining of the INTESTINAL MUCOSA. They are differentiated EPITHELIAL CELLS with apical MICROVILLI facing the intestinal lumen. Enterocytes are more abundant in the SMALL INTESTINE than in the LARGE INTESTINE. Their microvilli greatly increase the luminal surface area of the cell by 14- to 40 fold.
Physiological processes in biosynthesis (anabolism) and degradation (catabolism) of LIPIDS.
Conditions with excess LIPIDS in the blood.
A 513-kDa protein synthesized in the LIVER. It serves as the major structural protein of low-density lipoproteins (LIPOPROTEINS, LDL; LIPOPROTEINS, VLDL). It is the ligand for the LDL receptor (RECEPTORS, LDL) that promotes cellular binding and internalization of LDL particles.
Oils derived from plants or plant products.
Volume of biological fluid completely cleared of drug metabolites as measured in unit time. Elimination occurs as a result of metabolic processes in the kidney, liver, saliva, sweat, intestine, heart, brain, or other site.
Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.
A 9-kDa protein component of VERY-LOW-DENSITY LIPOPROTEINS and CHYLOMICRON REMNANTS. Apo C-III, synthesized in the liver, is an inhibitor of LIPOPROTEIN LIPASE. Apo C-III modulates the binding of chylomicron remnants and VLDL to receptors (RECEPTORS, LDL) thus decreases the uptake of triglyceride-rich particles by the liver cells and subsequent degradation. The normal Apo C-III is glycosylated. There are several polymorphic forms with varying amounts of SIALIC ACID (Apo C-III-0, Apo C-III-1, and Apo C-III-2).
A condition of elevated levels of TRIGLYCERIDES in the blood.
A class of protein components which can be found in several lipoproteins including HIGH-DENSITY LIPOPROTEINS; VERY-LOW-DENSITY LIPOPROTEINS; and CHYLOMICRONS. Synthesized in most organs, Apo E is important in the global transport of lipids and cholesterol throughout the body. Apo E is also a ligand for LDL receptors (RECEPTORS, LDL) that mediates the binding, internalization, and catabolism of lipoprotein particles in cells. There are several allelic isoforms (such as E2, E3, and E4). Deficiency or defects in Apo E are causes of HYPERLIPOPROTEINEMIA TYPE III.
An inherited condition due to a deficiency of either LIPOPROTEIN LIPASE or APOLIPOPROTEIN C-II (a lipase-activating protein). The lack of lipase activities results in inability to remove CHYLOMICRONS and TRIGLYCERIDES from the blood which has a creamy top layer after standing.
Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.
Oil from ZEA MAYS or corn plant.
A copolymer of polyethylene and polypropylene ether glycol. It is a non-ionic polyol surface-active agent used medically as a fecal softener and in cattle for prevention of bloat.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
The section of the alimentary canal from the STOMACH to the ANAL CANAL. It includes the LARGE INTESTINE and SMALL INTESTINE.
The portion of the GASTROINTESTINAL TRACT between the PYLORUS of the STOMACH and the ILEOCECAL VALVE of the LARGE INTESTINE. It is divisible into three portions: the DUODENUM, the JEJUNUM, and the ILEUM.
Tritium is an isotope of hydrogen (specifically, hydrogen-3) that contains one proton and two neutrons in its nucleus, making it radioactive with a half-life of about 12.3 years, and is used in various applications including nuclear research, illumination, and dating techniques due to its low energy beta decay.
Relating to the size of solids.
An unsaturated fatty acid that is the most widely distributed and abundant fatty acid in nature. It is used commercially in the preparation of oleates and lotions, and as a pharmaceutical solvent. (Stedman, 26th ed)
The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.
A highly acidic mucopolysaccharide formed of equal parts of sulfated D-glucosamine and D-glucuronic acid with sulfaminic bridges. The molecular weight ranges from six to twenty thousand. Heparin occurs in and is obtained from liver, lung, mast cells, etc., of vertebrates. Its function is unknown, but it is used to prevent blood clotting in vivo and vitro, in the form of many different salts.
A group of 16-carbon fatty acids that contain no double bonds.
Cholesterol present in food, especially in animal products.
The process of cleaving a chemical compound by the addition of a molecule of water.
LIPOLYSIS of stored LIPIDS in the ADIPOSE TISSUE to release FREE FATTY ACIDS. Mobilization of stored lipids is under the regulation of lipolytic signals (CATECHOLAMINES) or anti-lipolytic signals (INSULIN) via their actions on the hormone-sensitive LIPASE. This concept does not include lipid transport.
A nonionic polyoxyethylene-polyoxypropylene block co-polymer with the general formula HO(C2H4O)a(-C3H6O)b(C2H4O)aH. It is available in different grades which vary from liquids to solids. It is used as an emulsifying agent, solubilizing agent, surfactant, and wetting agent for antibiotics. Poloxamer is also used in ointment and suppository bases and as a tablet binder or coater. (Martindale The Extra Pharmacopoeia, 31st ed)
An autosomal recessively inherited disorder characterized by the accumulation of intermediate-density lipoprotein (IDL or broad-beta-lipoprotein). IDL has a CHOLESTEROL to TRIGLYCERIDES ratio greater than that of VERY-LOW-DENSITY LIPOPROTEINS. This disorder is due to mutation of APOLIPOPROTEINS E, a receptor-binding component of VLDL and CHYLOMICRONS, resulting in their reduced clearance and high plasma levels of both cholesterol and triglycerides.
Abstaining from all food.
Treatment process involving the injection of fluid into an organ or tissue.
A group of fatty acids that contain 18 carbon atoms and a double bond at the omega 9 carbon.
The process of converting an acid into an alkyl or aryl derivative. Most frequently the process consists of the reaction of an acid with an alcohol in the presence of a trace of mineral acid as catalyst or the reaction of an acyl chloride with an alcohol. Esterification can also be accomplished by enzymatic processes.
An iron-binding protein that was originally characterized as a milk protein. It is widely distributed in secretory fluids and is found in the neutrophilic granules of LEUKOCYTES. The N-terminal part of lactoferrin possesses a serine protease which functions to inactivate the TYPE III SECRETION SYSTEM used by bacteria to export virulence proteins for host cell invasion.
The glyceryl esters of a fatty acid, or of a mixture of fatty acids. They are generally odorless, colorless, and tasteless if pure, but they may be flavored according to origin. Fats are insoluble in water, soluble in most organic solvents. They occur in animal and vegetable tissue and are generally obtained by boiling or by extraction under pressure. They are important in the diet (DIETARY FATS) as a source of energy. (Grant & Hackh's Chemical Dictionary, 5th ed)
The rate dynamics in chemical or physical systems.
The middle portion of the SMALL INTESTINE, between DUODENUM and ILEUM. It represents about 2/5 of the remaining portion of the small intestine below duodenum.
"Esters are organic compounds that result from the reaction between an alcohol and a carboxylic acid, playing significant roles in various biological processes and often used in pharmaceutical synthesis."
Emulsions of fats or lipids used primarily in parenteral feeding.
Eighteen-carbon essential fatty acids that contain two double bonds.
The most abundant protein component of HIGH DENSITY LIPOPROTEINS or HDL. This protein serves as an acceptor for CHOLESTEROL released from cells thus promoting efflux of cholesterol to HDL then to the LIVER for excretion from the body (reverse cholesterol transport). It also acts as a cofactor for LECITHIN CHOLESTEROL ACYLTRANSFERASE that forms CHOLESTEROL ESTERS on the HDL particles. Mutations of this gene APOA1 cause HDL deficiency, such as in FAMILIAL ALPHA LIPOPROTEIN DEFICIENCY DISEASE and in some patients with TANGIER DISEASE.

Lipoprotein lipase expression level influences tissue clearance of chylomicron retinyl ester. (1/827)

Approximately 25% of postprandial retinoid is cleared from the circulation by extrahepatic tissues. Little is known about physiologic factors important to this uptake. We hypothesized that lipoprotein lipase (LpL) contributes to extrahepatic clearance of chylomicron vitamin A. To investigate this, [3H]retinyl ester-containing rat mesenteric chylomicrons were injected intravenously into induced mutant mice and nutritionally manipulated rats. The tissue sites of uptake of 3H label by wild type mice and LpL-null mice overexpressing human LpL in muscle indicate that LpL expression does influence accumulation of chylomicron retinoid. Skeletal muscle from mice overexpressing human LpL accumulated 1.7- to 2.4-fold more 3H label than wild type. Moreover, heart tissue from mice overexpresssing human LpL, but lacking mouse LpL, accumulated less than half of the 3H-label taken up by wild type heart. Fasting and heparin injection, two factors that increase LpL activity in skeletal muscle, increased uptake of chylomicron [3H] retinoid by rat skeletal muscle. Using [3H]retinyl palmitate and its non-hydrolyzable analog retinyl [14C]hexadecyl ether incorporated into Intralipid emulsions, the importance of retinyl ester hydrolysis in this process was assessed. We observed that 3H label was taken up to a greater extent than 14C label by rat skeletal muscle, suggesting that retinoid uptake requires hydrolysis. In summary, for each of our experiments, the level of lipoprotein lipase expression in skeletal muscle, heart, and/or adipose tissue influenced the amount of [3H]retinoid taken up from chylomicrons and/or their remnants.  (+info)

Plasma clearance and liver uptake of chylomicron remnants generated by hepatic lipase lipolysis: evidence for a lactoferrin-sensitive and apolipoprotein E-independent pathway. (2/827)

Chylomicrons labeled with [3H]cholesterol and [14C]triglyceride fatty acids were lipolyzed by hepatic lipase (HL) in vitro and then injected intravenously into normal mice fed low- or high-fat diets, and into apolipoprotein (apo) E-deficient mice. In normal mice fed the high-fat diet and injected with non-lipolyzed chylomicrons, the plasma clearance and hepatic uptake of the resulting [3H]cholesterol-labeled remnants was markedly inhibited. In contrast, chylomicrons lipolyzed by HL were taken up equally rapidly by the livers of mice fed the low- and high-fat diets. The removal of non-lipolyzed chylomicrons lacking apoE from the plasma of apoE-deficient mice was inhibited, but not the removal of chylomicrons lipolyzed by HL. Pre-injection of lactoferrin into normal mice inhibited the plasma clearance of both non-lipolyzed chylomicrons and chylomicrons lipolyzed by HL. The removal of HL from the surface of the lipolyzed particles by proteolytic digestion did not affect their rapid uptake, indicating that the hepatic recognition of the lipoproteins was not mediated by HL. These observations support previous findings that phospholipolysis of chylomicrons by hepatic lipase generates remnant particles that are rapidly cleared from circulation by the liver. They also support the concept that chylomicron remnants can be taken up by the liver by an apolipoprotein E-independent mechanism. We hypothesize that this mechanism is modulated by the remnant phospholipids and that it may involve their interaction with a phospholipid-binding receptor on the surface of hepatocytes such as the class B scavenger receptor BI.  (+info)

Effects of a frequent apolipoprotein E isoform, ApoE4Freiburg (Leu28-->Pro), on lipoproteins and the prevalence of coronary artery disease in whites. (3/827)

Different isoforms of apoE modulate the concentrations of plasma lipoproteins and the risk for atherosclerosis. A novel apoE isoform, apoE4Freiburg, was detected in plasma by isoelectric focusing because its isoelectric point is slightly more acidic than that of apoE4. ApoE4Freiburg results from a base exchange in the APOE4 gene that causes the replacement of a leucine by a proline at position 28. Analysis of the allelic frequencies in whites in southwestern Germany revealed that this isoform is frequent among control subjects (10:4264 alleles) and is even more frequent in patients with coronary artery disease (21:2874 alleles; P=0.004; adjusted odds ratio, 3.09; 95% confidence interval, 1.20 to 7.97). ApoE4Freiburg affects serum lipoproteins by lowering cholesterol, apoB, and apoA-I compared with apoE4 (P<0.05). Our 4 apoE4Freiburg homozygotes suffered from various phenotypes of hyperlipoproteinemia (types IIa, IIb, IV, and V). In vitro binding studies excluded a binding defect of apoE4Freiburg, and in vivo studies excluded an abnormal accumulation of chylomicron remnants. ApoE4Freiburg and apoE4 accumulated to a similar extent in triglyceride-rich lipoproteins. HDLs, however, contained about 40% less apoE4Freiburg than apoE4. In conclusion, our data indicate that apoE4Freiburg exerts its possible atherogenic properties by affecting the metabolism of triglyceride-rich lipoproteins and HDL.  (+info)

Very low-density lipoprotein activates nuclear factor-kappaB in endothelial cells. (4/827)

High plasma levels of VLDL are associated with increased risk for atherosclerosis. Here we show that VLDL (75 to 150 microg/mL) activates nuclear factor-kappaB (NF-kappaB), a transcription factor known to play a key role in regulation of inflammation. Oxidation of VLDL reduced its capacity to activate NF-kappaB in vitro, whereas free fatty acids such as linoleic and oleic acid activated NF-kappaB to the same extent as did VLDL. Intravenous injection of human VLDL (6 mg protein per kg) into rats resulted in arterial activation of NF-kappaB as assessed by electrophoretic mobility shift assay. Aortic endothelial cells showed positive nuclear staining for the activated RelA (p65) subunit of NF-kappaB at 6 to 24 hours after injection. There was also a parallel expression of the adhesion molecules intercellular adhesion molecule-1 and vascular cell adhesion molecule-1, as well as the cytokine tumor necrosis factor-alpha. Pretreatment of the rats with diet containing 1% of the antioxidant probucol for 8 weeks did not inhibit arterial activation of NF-kappaB in response to injection of VLDL. Moreover, injection of triglycerides (10% Intralipid, 5 mL/kg) activated arterial expression of NF-kappaB to the same extent as VLDL. Our results suggest that VLDL may promote the development of atherosclerotic lesions by activation of the proinflammatory transcription factor NF-kappaB. The effect appears to be mediated by a release of VLDL fatty acids but not to involve VLDL oxidation.  (+info)

Effect of oxidized lipids in the diet on oxidized lipid levels in postprandial serum chylomicrons of diabetic patients. (5/827)

OBJECTIVE: To determine whether humans with type 2 diabetes have increased levels of oxidized fatty acids in their serum chylomicron fraction after the ingestion of dietary oxidized fatty acids. RESEARCH DESIGN AND METHODS: The study was performed on 31 male type 2 diabetic patients and 24 age-matched control subjects. Among the diabetic patients, 22 had poor glycemic control, defined as HbA1 > 10% (normal value < 7.7%). Nine patients had good glycemic control (HbA1 < or = 10). Heated corn oil containing low or high levels of oxidized fatty acids was used as a test meal. At 2.5 h after the test meal, 50-ml blood samples were obtained from all subjects, and the chylomicron fraction (Sf > 1,000) was isolated. The degree of oxidation in chylomicrons was determined by measuring conjugated dienes. For determining the postprandial levels of triglycerides and of oxidized lipids in serum chylomicrons over an extended time period, blood samples were obtained at 0, 2.5, 5.0, and 7.5 h for isolation of chylomicrons and determination of fatty acid oxidation. RESULTS: We found that at 2.5 h after the consumption of the test meal containing either a low or high oxidized fatty acid content, conjugated dienes in serum chylomicrons in diabetic subjects in poor glycemic control were increased compared with those in control subjects. Diabetic patients in good glycemic control had similar levels of oxidized lipid in their chylomicrons when compared with control subjects. Additionally, in diabetic patients in poor glycemic control, the levels of oxidized lipids in chylomicrons remained elevated for an extended post-prandial period. CONCLUSIONS: In diabetic subjects with poor glycemic control, dietary oxidized lipids induce an exaggerated and sustained increase in the levels of oxidized lipids in chylomicrons when compared with either control subjects or diabetic patients with good glycemic control. These increased postprandial levels of potentially atherogenic oxidized lipids may contribute to the accelerated atherosclerosis associated with diabetes.  (+info)

Plasma clearance of chylomicrons from butterfat is not dependent on saturation: studies with butterfat fractions and other fats containing triacylglycerols with low or high melting points. (6/827)

BACKGROUND: Dietary fats influence plasma lipids, and changes in the clearance and metabolism of postprandial lipoproteins can affect atherosclerosis. Butterfat is considered hypercholesterolemic but contains a multitude of constituent fatty acids. OBJECTIVES: We determined triacylglycerol and cholesteryl ester clearances of lymph chylomicrons derived from butterfat, fractions of butterfat, and other dietary fats. METHODS: Radiolabeled lymph chylomicrons resulting from the intestinal absorption of different fats were reinjected into recipient rats to measure plasma clearance. Plasma clearance of [14C]triacylglycerol was used as an indicator of chylomicron lipolysis whereas clearance of [3H]cholesteryl ester was used as an indicator of chylomicron remnant removal. RESULTS: [3H]Cholesteryl ester clearance was slower from chylomicrons derived from a solid, high-saturated-butterfat fraction than from whole butterfat, but clearance of chylomicrons from other fractions did not correlate with the fractions' saturated fatty acid contents. Clearance of cholesteryl esters in chylomicrons derived from cocoa butter, palm oil, and butterfat was slower than clearance of cholesteryl esters in chylomicrons derived from safflower oil. Hepatic uptakes of cholesteryl esters were generally lower for chylomicrons from all butterfat fractions, cocoa butter, and palm oil. CONCLUSIONS: In contrast with minor effects on the lipolysis of chylomicron triacylglycerols, chylomicron remnant removal was strongly influenced by the type of dietary fat, with slower cholesteryl ester clearances for saturated fats with higher melting points. However, remnant removal and hepatic uptake of chylomicrons from whole butterfat and fractions of butterfat were not correlated with fat saturation. The mechanisms of this apparent paradox remain unknown but may be attributable to acyl arrangements in the lipid classes of chylomicrons that influence the association with apolipoproteins and receptors and hence remnant removal.  (+info)

All ApoB-containing lipoproteins induce monocyte chemotaxis and adhesion when minimally modified. Modulation of lipoprotein bioactivity by platelet-activating factor acetylhydrolase. (7/827)

Mildly oxidized LDL has many proinflammatory properties, including the stimulation of monocyte chemotaxis and adhesion, that are important in the development of atherosclerosis. Although ApoB-containing lipoproteins other than LDL may enter the artery wall and undergo oxidation, very little is known regarding their proinflammatory potential. LDL, IDL, VLDL, postprandial remnant particles, and chylomicrons were mildly oxidized by fibroblasts overexpressing 15-lipoxygenase (15-LO) and tested for their ability to stimulate monocyte chemotaxis and adhesion to endothelial cells. When conditioned on 15-LO cells, LDL, IDL, but not VLDL increased monocyte chemotaxis and adhesion approximately 4-fold. Chylomicrons and postprandial remnant particles were also bioactive. Although chylomicrons had a high 18:1/18:2 ratio, similar to that of VLDL, and should presumably be less susceptible to oxidation, they contained (in contrast to VLDL) essentially no platelet-activating factor acetylhydrolase (PAF-AH) activity. Because PAF-AH activity of lipoproteins may be reduced in vivo by oxidation or glycation, LDL, IDL, and VLDL were treated in vitro to reduce PAF-AH activity and then conditioned on 15-lipoxygenase cells. All 3 PAF-AH-depleted lipoproteins, including VLDL, exhibited increased stimulation of monocyte chemotaxis and adhesion. In a similar manner, lipoproteins from Japanese subjects with a deficiency of plasma PAF-AH activity were also markedly more bioactive, and stimulated monocyte adhesion nearly 2-fold compared with lipoproteins from Japanese control subjects with normal plasma PAF-AH. For each lipoprotein, bioactivity resided in the lipid fraction and monocyte adhesion could be blocked by PAF-receptor antagonists. These data suggest that the susceptibility of plasma lipoproteins to develop proinflammatory activity is in part related to their 18:1/18:2 ratio and PAF-AH activity, and that bioactive phospholipids similar to PAF are generated during oxidation of each lipoprotein. Moreover, LDL, IDL, postprandial remnant particles, and chylomicrons and PAF-AH-depleted VLDL all give rise to proinflammatory lipids when mildly oxidized.  (+info)

Mutations in the lipoprotein lipase gene associated with ischemic heart disease in men. The Copenhagen city heart study. (8/827)

The aim of this study was to test the hypothesis that the Asp9Asn substitution and the T(-93)-->G mutation in the promoter of the lipoprotein lipase gene affect plasma lipid levels and thereby the risk of ischemic heart disease (IHD). We genotyped 9033 men and women from a general population sample and 940 patients with IHD. The frequency of both the G allele and the Asn9 allele in the general population sample was approximately 0.015 for both men and women. These 2 mutations appeared together in 95% of carriers. The average triglyceride-raising effect associated with double heterozygosity for the T(-93)-->G mutation and the Asp9Asn substitution was 0.28 mmol/L (P=0.004) and 0.16 mmol/L (P=0.10) in men and women, respectively. On logistic regression analysis allowing for age, the risk of IHD for double heterozygous men and women was increased 90% (95% confidence interval [CI], 20% to 200%) and 30% (95% CI, -40% to 170%), respectively, compared with noncarriers. When, in addition, other conventional cardiovascular risk factors were allowed for, the risk of IHD for double heterozygous men and women was increased 70% (95% CI, 0% to 190%) and 20% (95% CI, -50% to 180%), respectively. Of the overall risk of IHD in men in the general population, the fraction attributable to double heterozygosity was 3%, similar to the 5% attributable to diabetes mellitus. These results demonstrate that the Asp9Asn substitution is in linkage disequilibrium with the T(-93)-->G mutation and that the double-heterozygous carrier status is associated with elevated plasma triglycerides and an increased risk of IHD in men.  (+info)

Chylomicrons are a type of lipoprotein that are responsible for carrying dietary lipids, such as triglycerides and cholesterol, from the intestines to other parts of the body through the lymphatic system and bloodstream. They are the largest lipoproteins and are composed of an outer layer of phospholipids, free cholesterol, and apolipoproteins, which surrounds a core of triglycerides and cholesteryl esters. Chylomicrons are produced in the intestinal mucosa after a meal containing fat, and their production is stimulated by the hormone cholecystokinin. Once in the bloodstream, chylomicrons interact with other lipoproteins and enzymes to deliver their lipid cargo to various tissues, including muscle and adipose tissue, where they are used for energy or stored for later use.

Lymph is a colorless, transparent fluid that circulates throughout the lymphatic system, which is a part of the immune and circulatory systems. It consists of white blood cells called lymphocytes, proteins, lipids, glucose, electrolytes, hormones, and waste products. Lymph plays an essential role in maintaining fluid balance, absorbing fats from the digestive tract, and defending the body against infection by transporting immune cells to various tissues and organs. It is collected from tissues through lymph capillaries and flows through increasingly larger lymphatic vessels, ultimately returning to the bloodstream via the subclavian veins in the chest region.

Chyle is a milky, slightly opaque fluid that is present in the lymphatic system. It is formed in the small intestine during the digestion of food, particularly fats. Chyle consists of emulsified fat droplets (chylomicrons), proteins, electrolytes, and lymphocytes suspended in a watery solution. It is transported through the lacteals in the villi of the small intestine into the cisterna chyli and then to the thoracic duct, where it empties into the left subclavian vein. From there, it mixes with blood and circulates throughout the body. Chyle formation plays a crucial role in fat absorption and transportation in the human body.

Triglycerides are the most common type of fat in the body, and they're found in the food we eat. They're carried in the bloodstream to provide energy to the cells in our body. High levels of triglycerides in the blood can increase the risk of heart disease, especially in combination with other risk factors such as high LDL (bad) cholesterol, low HDL (good) cholesterol, and high blood pressure.

It's important to note that while triglycerides are a type of fat, they should not be confused with cholesterol, which is a waxy substance found in the cells of our body. Both triglycerides and cholesterol are important for maintaining good health, but high levels of either can increase the risk of heart disease.

Triglyceride levels are measured through a blood test called a lipid panel or lipid profile. A normal triglyceride level is less than 150 mg/dL. Borderline-high levels range from 150 to 199 mg/dL, high levels range from 200 to 499 mg/dL, and very high levels are 500 mg/dL or higher.

Elevated triglycerides can be caused by various factors such as obesity, physical inactivity, excessive alcohol consumption, smoking, and certain medical conditions like diabetes, hypothyroidism, and kidney disease. Medications such as beta-blockers, steroids, and diuretics can also raise triglyceride levels.

Lifestyle changes such as losing weight, exercising regularly, eating a healthy diet low in saturated and trans fats, avoiding excessive alcohol consumption, and quitting smoking can help lower triglyceride levels. In some cases, medication may be necessary to reduce triglycerides to recommended levels.

Lipoprotein lipase (LPL) is an enzyme that plays a crucial role in the metabolism of lipids. It is responsible for breaking down triglycerides, which are the main constituent of dietary fats and chylomicrons, into fatty acids and glycerol. These products are then taken up by cells for energy production or storage.

LPL is synthesized in various tissues, including muscle and fat, where it is attached to the inner lining of blood vessels (endothelium). The enzyme is activated when it comes into contact with lipoprotein particles, such as chylomicrons and very-low-density lipoproteins (VLDL), which transport triglycerides in the bloodstream.

Deficiencies or mutations in LPL can lead to various metabolic disorders, including hypertriglyceridemia, a condition characterized by high levels of triglycerides in the blood. Conversely, overexpression of LPL has been associated with increased risk of atherosclerosis due to excessive uptake of fatty acids by macrophages and their conversion into foam cells, which contribute to plaque formation in the arteries.

Apolipoprotein B-48 (apoB-48) is a protein component of chylomicrons, which are lipoprotein particles responsible for carrying dietary fat and cholesterol from the intestines to other parts of the body. ApoB-48 is produced in the intestines and is a shorter version of apolipoprotein B-100 (apoB-100), which is a component of low-density lipoproteins (LDL) or "bad cholesterol."

Chylomicrons are assembled and secreted by intestinal cells after a meal, and apoB-48 is essential for the formation and function of these particles. ApoB-48-containing chylomicrons transport dietary lipids to various tissues, including the liver, where they contribute to the maintenance of lipid homeostasis.

Elevated levels of apoB-48 in the blood have been associated with an increased risk of cardiovascular disease, particularly in individuals with familial chylomicronemia syndrome (FCS), a rare genetic disorder characterized by severely elevated triglyceride levels due to impaired clearance of chylomicrons.

VLDL (Very Low-Density Lipoproteins) are a type of lipoprotein that play a crucial role in the transport and metabolism of fat molecules, known as triglycerides, in the body. They are produced by the liver and consist of a core of triglycerides surrounded by a shell of proteins called apolipoproteins, phospholipids, and cholesterol.

VLDL particles are responsible for delivering fat molecules from the liver to peripheral tissues throughout the body, where they can be used as an energy source or stored for later use. During this process, VLDL particles lose triglycerides and acquire more cholesterol, transforming into intermediate-density lipoproteins (IDL) and eventually low-density lipoproteins (LDL), which are also known as "bad" cholesterol.

Elevated levels of VLDL in the blood can contribute to the development of cardiovascular disease due to their association with increased levels of triglycerides and LDL cholesterol, as well as decreased levels of high-density lipoproteins (HDL), which are considered "good" cholesterol.

Lipoproteins are complex particles composed of multiple proteins and lipids (fats) that play a crucial role in the transport and metabolism of fat molecules in the body. They consist of an outer shell of phospholipids, free cholesterols, and apolipoproteins, enclosing a core of triglycerides and cholesteryl esters.

There are several types of lipoproteins, including:

1. Chylomicrons: These are the largest lipoproteins and are responsible for transporting dietary lipids from the intestines to other parts of the body.
2. Very-low-density lipoproteins (VLDL): Produced by the liver, VLDL particles carry triglycerides to peripheral tissues for energy storage or use.
3. Low-density lipoproteins (LDL): Often referred to as "bad cholesterol," LDL particles transport cholesterol from the liver to cells throughout the body. High levels of LDL in the blood can lead to plaque buildup in artery walls and increase the risk of heart disease.
4. High-density lipoproteins (HDL): Known as "good cholesterol," HDL particles help remove excess cholesterol from cells and transport it back to the liver for excretion or recycling. Higher levels of HDL are associated with a lower risk of heart disease.

Understanding lipoproteins and their roles in the body is essential for assessing cardiovascular health and managing risks related to heart disease and stroke.

Apolipoproteins are a group of proteins that are associated with lipids (fats) in the body and play a crucial role in the metabolism, transportation, and regulation of lipids. They are structural components of lipoprotein particles, which are complexes of lipids and proteins that transport lipids in the bloodstream.

There are several types of apolipoproteins, including ApoA, ApoB, ApoC, ApoD, ApoE, and others. Each type has a specific function in lipid metabolism. For example, ApoA is a major component of high-density lipoprotein (HDL), often referred to as "good cholesterol," and helps remove excess cholesterol from cells and tissues and transport it to the liver for excretion. ApoB, on the other hand, is a major component of low-density lipoprotein (LDL), or "bad cholesterol," and plays a role in the delivery of cholesterol to cells and tissues.

Abnormal levels of apolipoproteins or dysfunctional forms of these proteins have been linked to various diseases, including cardiovascular disease, Alzheimer's disease, and metabolic disorders such as diabetes. Therefore, measuring apolipoprotein levels in the blood can provide valuable information for diagnosing and monitoring these conditions.

An emulsion is a type of stable mixture of two immiscible liquids, such as oil and water, which are normally unable to mix together uniformly. In an emulsion, one liquid (the dispersed phase) is broken down into small droplets and distributed throughout the other liquid (the continuous phase), creating a stable, cloudy mixture.

In medical terms, emulsions can be used in various pharmaceutical and cosmetic applications. For example, certain medications may be formulated as oil-in-water or water-in-oil emulsions to improve their absorption, stability, or palatability. Similarly, some skincare products and makeup removers contain emulsifiers that help create stable mixtures of water and oils, allowing for effective cleansing and moisturizing.

Emulsions can also occur naturally in the body, such as in the digestion of fats. The bile salts produced by the liver help to form small droplets of dietary lipids (oil) within the watery environment of the small intestine, allowing for efficient absorption and metabolism of these nutrients.

Dietary fats, also known as fatty acids, are a major nutrient that the body needs for energy and various functions. They are an essential component of cell membranes and hormones, and they help the body absorb certain vitamins. There are several types of dietary fats:

1. Saturated fats: These are typically solid at room temperature and are found in animal products such as meat, butter, and cheese, as well as tropical oils like coconut and palm oil. Consuming a high amount of saturated fats can raise levels of unhealthy LDL cholesterol and increase the risk of heart disease.
2. Unsaturated fats: These are typically liquid at room temperature and can be further divided into monounsaturated and polyunsaturated fats. Monounsaturated fats, found in foods such as olive oil, avocados, and nuts, can help lower levels of unhealthy LDL cholesterol while maintaining levels of healthy HDL cholesterol. Polyunsaturated fats, found in foods such as fatty fish, flaxseeds, and walnuts, have similar effects on cholesterol levels and also provide essential omega-3 and omega-6 fatty acids that the body cannot produce on its own.
3. Trans fats: These are unsaturated fats that have been chemically modified to be solid at room temperature. They are often found in processed foods such as baked goods, fried foods, and snack foods. Consuming trans fats can raise levels of unhealthy LDL cholesterol and lower levels of healthy HDL cholesterol, increasing the risk of heart disease.

It is recommended to limit intake of saturated and trans fats and to consume more unsaturated fats as part of a healthy diet.

Apolipoprotein B (ApoB) is a type of protein that plays a crucial role in the metabolism of lipids, particularly low-density lipoprotein (LDL) or "bad" cholesterol. ApoB is a component of LDL particles and serves as a ligand for the LDL receptor, which is responsible for the clearance of LDL from the bloodstream.

There are two main forms of ApoB: ApoB-100 and ApoB-48. ApoB-100 is found in LDL particles, very low-density lipoprotein (VLDL) particles, and chylomicrons, while ApoB-48 is only found in chylomicrons, which are produced in the intestines and responsible for transporting dietary lipids.

Elevated levels of ApoB are associated with an increased risk of cardiovascular disease (CVD), as they indicate a higher concentration of LDL particles in the bloodstream. Therefore, measuring ApoB levels can provide additional information about CVD risk beyond traditional lipid profile tests that only measure total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides.

Cholesterol is a type of lipid (fat) molecule that is an essential component of cell membranes and is also used to make certain hormones and vitamins in the body. It is produced by the liver and is also obtained from animal-derived foods such as meat, dairy products, and eggs.

Cholesterol does not mix with blood, so it is transported through the bloodstream by lipoproteins, which are particles made up of both lipids and proteins. There are two main types of lipoproteins that carry cholesterol: low-density lipoproteins (LDL), also known as "bad" cholesterol, and high-density lipoproteins (HDL), also known as "good" cholesterol.

High levels of LDL cholesterol in the blood can lead to a buildup of cholesterol in the walls of the arteries, increasing the risk of heart disease and stroke. On the other hand, high levels of HDL cholesterol are associated with a lower risk of these conditions because HDL helps remove LDL cholesterol from the bloodstream and transport it back to the liver for disposal.

It is important to maintain healthy levels of cholesterol through a balanced diet, regular exercise, and sometimes medication if necessary. Regular screening is also recommended to monitor cholesterol levels and prevent health complications.

The thoracic duct is the largest lymphatic vessel in the human body. It is a part of the lymphatic system, which helps to regulate fluid balance and immune function. The thoracic duct originates from the cisterna chyli, a dilated sac located in the abdomen near the aorta.

The thoracic duct collects lymph from the lower extremities, abdomen, pelvis, and left side of the thorax (chest). It ascends through the diaphragm and enters the chest, where it passes through the mediastinum (the central part of the chest between the lungs) and eventually drains into the left subclavian vein.

The thoracic duct plays a crucial role in transporting lymphatic fluid, which contains white blood cells, fats, proteins, and other substances, back into the circulatory system. Any obstruction or damage to the thoracic duct can lead to lymph accumulation in the surrounding tissues, causing swelling and other symptoms.

Medical Definition of Vitamin A:

Vitamin A is a fat-soluble vitamin that is essential for normal vision, immune function, and cell growth. It is also an antioxidant that helps protect the body's cells from damage caused by free radicals. Vitamin A can be found in two main forms: preformed vitamin A, which is found in animal products such as dairy, fish, and meat, particularly liver; and provitamin A carotenoids, which are found in plant-based foods such as fruits, vegetables, and vegetable oils.

The most active form of vitamin A is retinoic acid, which plays a critical role in the development and maintenance of the heart, lungs, kidneys, and other organs. Vitamin A deficiency can lead to night blindness, dry skin, and increased susceptibility to infections. Chronic vitamin A toxicity can cause nausea, dizziness, headaches, coma, and even death.

In the context of medicine and pharmacology, oils are typically defined as lipid-based substances that are derived from plants or animals. They are made up of molecules called fatty acids, which can be either saturated or unsaturated. Oils are often used in medical treatments and therapies due to their ability to deliver active ingredients through the skin, as well as their moisturizing and soothing properties. Some oils, such as essential oils, are also used in aromatherapy for their potential therapeutic benefits. However, it's important to note that some oils can be toxic or irritating if ingested or applied to the skin in large amounts, so they should always be used with caution and under the guidance of a healthcare professional.

The postprandial period is the time frame following a meal, during which the body is engaged in the process of digestion, absorption, and assimilation of nutrients. In a medical context, this term generally refers to the few hours after eating when the body is responding to the ingested food, particularly in terms of changes in metabolism and insulin levels.

The postprandial period can be of specific interest in the study and management of conditions such as diabetes, where understanding how the body handles glucose during this time can inform treatment decisions and strategies for maintaining healthy blood sugar levels.

Apolipoprotein C (apoC) is a group of proteins that are associated with lipoproteins, which are complex particles composed of lipids and proteins that play a crucial role in the transport and metabolism of lipids in the body. There are three main types of apoC proteins: apoC-I, apoC-II, and apoC-III.

ApoC-I is involved in the regulation of lipoprotein metabolism and has been shown to inhibit the activity of cholesteryl ester transfer protein (CETP), which is an enzyme that facilitates the transfer of cholesteryl esters from high-density lipoproteins (HDL) to low-density lipoproteins (LDL) and very low-density lipoproteins (VLDL).

ApoC-II is a cofactor for lipoprotein lipase, an enzyme that hydrolyzes triglycerides in chylomicrons and VLDL, leading to the formation of smaller, denser lipoproteins. A deficiency in apoC-II can lead to hypertriglyceridemia, a condition characterized by elevated levels of triglycerides in the blood.

ApoC-III is also involved in the regulation of lipoprotein metabolism and has been shown to inhibit the activity of lipoprotein lipase and CETP. Elevated levels of apoC-III have been associated with an increased risk of cardiovascular disease, possibly due to its effects on lipoprotein metabolism.

In summary, apolipoprotein C is a group of proteins that are involved in the regulation of lipoprotein metabolism and have important roles in the transport and metabolism of lipids in the body.

High-Density Lipoproteins (HDL) are a type of lipoprotein that play a crucial role in the transportation and metabolism of cholesterol in the body. They are often referred to as "good" cholesterol because they help remove excess cholesterol from cells and carry it back to the liver, where it can be broken down and removed from the body. This process is known as reverse cholesterol transport.

HDLs are composed of a lipid core containing cholesteryl esters and triglycerides, surrounded by a shell of phospholipids, free cholesterol, and apolipoproteins, primarily apoA-I. The size and composition of HDL particles can vary, leading to the classification of different subclasses of HDL with varying functions and metabolic fates.

Elevated levels of HDL have been associated with a lower risk of developing cardiovascular diseases, while low HDL levels increase the risk. However, it is essential to consider that HDL function and quality may be more important than just the quantity in determining cardiovascular risk.

Cholesteryl esters are formed when cholesterol, a type of lipid (fat) that is important for the normal functioning of the body, becomes combined with fatty acids through a process called esterification. This results in a compound that is more hydrophobic (water-repelling) than cholesterol itself, which allows it to be stored more efficiently in the body.

Cholesteryl esters are found naturally in foods such as animal fats and oils, and they are also produced by the liver and other cells in the body. They play an important role in the structure and function of cell membranes, and they are also precursors to the synthesis of steroid hormones, bile acids, and vitamin D.

However, high levels of cholesteryl esters in the blood can contribute to the development of atherosclerosis, a condition characterized by the buildup of plaque in the arteries, which can increase the risk of heart disease and stroke. Cholesteryl esters are typically measured as part of a lipid profile, along with other markers such as total cholesterol, HDL cholesterol, and triglycerides.

Lipolysis is the process by which fat cells (adipocytes) break down stored triglycerides into glycerol and free fatty acids. This process occurs when the body needs to use stored fat as a source of energy, such as during fasting, exercise, or in response to certain hormonal signals. The breakdown products of lipolysis can be used directly by cells for energy production or can be released into the bloodstream and transported to other tissues for use. Lipolysis is regulated by several hormones, including adrenaline (epinephrine), noradrenaline (norepinephrine), cortisol, glucagon, and growth hormone, which act on lipases, enzymes that mediate the breakdown of triglycerides.

Intestinal absorption refers to the process by which the small intestine absorbs water, nutrients, and electrolytes from food into the bloodstream. This is a critical part of the digestive process, allowing the body to utilize the nutrients it needs and eliminate waste products. The inner wall of the small intestine contains tiny finger-like projections called villi, which increase the surface area for absorption. Nutrients are absorbed into the bloodstream through the walls of the capillaries in these villi, and then transported to other parts of the body for use or storage.

Apolipoprotein A (apoA) is a type of apolipoprotein that is primarily associated with high-density lipoproteins (HDL), often referred to as "good cholesterol." There are several subtypes of apoA, including apoA-I, apoA-II, and apoA-IV.

ApoA-I is the major protein component of HDL particles and plays a crucial role in reverse cholesterol transport, which is the process by which excess cholesterol is removed from tissues and delivered to the liver for excretion. Low levels of apoA-I have been linked to an increased risk of cardiovascular disease.

ApoA-II is another protein component of HDL particles, although its function is less well understood than that of apoA-I. Some studies suggest that apoA-II may play a role in regulating the metabolism of HDL particles.

ApoA-IV is found in both HDL and chylomicrons, which are lipoprotein particles that transport dietary lipids from the intestine to the liver. The function of apoA-IV is not well understood, but it may play a role in regulating appetite and energy metabolism.

Overall, apolipoproteins A are important components of HDL particles and play a critical role in maintaining healthy lipid metabolism and reducing the risk of cardiovascular disease.

Triolein is a type of triglyceride, which is a kind of fat molecule. More specifically, triolein is the triglyceride formed from three molecules of oleic acid, a common monounsaturated fatty acid. It is often used in scientific research and studies involving lipid metabolism, and it can be found in various vegetable oils and animal fats.

The liver is a large, solid organ located in the upper right portion of the abdomen, beneath the diaphragm and above the stomach. It plays a vital role in several bodily functions, including:

1. Metabolism: The liver helps to metabolize carbohydrates, fats, and proteins from the food we eat into energy and nutrients that our bodies can use.
2. Detoxification: The liver detoxifies harmful substances in the body by breaking them down into less toxic forms or excreting them through bile.
3. Synthesis: The liver synthesizes important proteins, such as albumin and clotting factors, that are necessary for proper bodily function.
4. Storage: The liver stores glucose, vitamins, and minerals that can be released when the body needs them.
5. Bile production: The liver produces bile, a digestive juice that helps to break down fats in the small intestine.
6. Immune function: The liver plays a role in the immune system by filtering out bacteria and other harmful substances from the blood.

Overall, the liver is an essential organ that plays a critical role in maintaining overall health and well-being.

Apoproteins are the protein components of lipoprotein complexes, which are responsible for transporting fat molecules, such as cholesterol and triglycerides, throughout the body. Apoproteins play a crucial role in the metabolism of lipids by acting as recognition signals that allow lipoproteins to interact with specific receptors on cell surfaces.

There are several different types of apoproteins, each with distinct functions. For example, apolipoprotein A-1 (apoA-1) is the major protein component of high-density lipoproteins (HDL), which are responsible for transporting excess cholesterol from tissues to the liver for excretion. Apolipoprotein B (apoB) is a large apoprotein found in low-density lipoproteins (LDL), very low-density lipoproteins (VLDL), and lipoprotein(a). ApoB plays a critical role in the assembly and secretion of VLDL from the liver, and it also mediates the uptake of LDL by cells.

Abnormalities in apoprotein levels or function can contribute to the development of various diseases, including cardiovascular disease, diabetes, and Alzheimer's disease. Therefore, measuring apoprotein levels in the blood can provide valuable information for diagnosing and monitoring these conditions.

Apolipoprotein C-II (ApoC-II) is a type of apolipoprotein, which are proteins that bind to lipids to form lipoprotein complexes. ApoC-II is a component of several lipoproteins, including very low-density lipoproteins (VLDL) and chylomicrons, which are responsible for the transport of fat molecules, such as triglycerides and cholesterol, in the bloodstream.

ApoC-II plays a crucial role in the activation of lipoprotein lipase, an enzyme that breaks down triglycerides in VLDL and chylomicrons into fatty acids, which can then be taken up by cells for energy production or storage. Therefore, ApoC-II deficiency can lead to hypertriglyceridemia, a condition characterized by high levels of triglycerides in the blood.

In addition to its role in lipid metabolism, ApoC-II has been implicated in the development and progression of atherosclerosis, a chronic inflammatory disease that affects the arteries and can lead to serious cardiovascular complications, such as heart attack and stroke.

Lipoprotein receptors are specialized proteins found on the surface of cells that play a crucial role in the metabolism of lipoproteins, which are complex particles composed of lipids and proteins. These receptors bind to specific lipoproteins in the bloodstream, facilitating their uptake into the cell for further processing.

There are several types of lipoprotein receptors, including:

1. LDL (Low-Density Lipoprotein) Receptor: This receptor is responsible for recognizing and internalizing LDL particles, which are rich in cholesterol. Once inside the cell, LDL particles release their cholesterol, which can then be used for various cellular functions or stored for later use. Defects in the LDL receptor can lead to elevated levels of LDL cholesterol in the blood and an increased risk of developing cardiovascular disease.
2. HDL (High-Density Lipoprotein) Receptor: This receptor is involved in the clearance of HDL particles from the bloodstream. HDL particles are responsible for transporting excess cholesterol from peripheral tissues to the liver, where it can be processed and eliminated from the body.
3. VLDL (Very Low-Density Lipoprotein) Receptor: This receptor recognizes and internalizes VLDL particles, which are produced by the liver and carry triglycerides and cholesterol to peripheral tissues. VLDL particles are subsequently converted into LDL particles in the bloodstream.
4. LRP (Low-Density Lipoprotein Receptor-Related Protein) Family: This family of receptors includes several members, such as LRP1 and LRP2, that play roles in various cellular processes, including lipid metabolism, protein trafficking, and cell signaling. They can bind to a variety of ligands, including lipoproteins, proteases, and extracellular matrix components.

In summary, lipoprotein receptors are essential for maintaining proper lipid metabolism and homeostasis by facilitating the uptake, processing, and elimination of lipoproteins in the body.

Low-density lipoproteins (LDL), also known as "bad cholesterol," are a type of lipoprotein that carry cholesterol and other fats from the liver to cells throughout the body. High levels of LDL in the blood can lead to the buildup of cholesterol in the walls of the arteries, which can increase the risk of heart disease and stroke.

Lipoproteins are complex particles composed of proteins (apolipoproteins) and lipids (cholesterol, triglycerides, and phospholipids) that are responsible for transporting fat molecules around the body in the bloodstream. LDL is one type of lipoprotein, along with high-density lipoproteins (HDL), very low-density lipoproteins (VLDL), and chylomicrons.

LDL particles are smaller than HDL particles and can easily penetrate the artery walls, leading to the formation of plaques that can narrow or block the arteries. Therefore, maintaining healthy levels of LDL in the blood is essential for preventing cardiovascular disease.

Blood protein disorders refer to a group of medical conditions that affect the production or function of proteins in the blood. These proteins are crucial for maintaining the proper functioning of the body's immune system, transporting nutrients, and preventing excessive bleeding. Some examples of blood protein disorders include:

1. Hemophilia: A genetic disorder caused by a deficiency or absence of clotting factors in the blood, leading to prolonged bleeding and poor clot formation.
2. Von Willebrand disease: A genetic disorder characterized by abnormal or deficient von Willebrand factor, which is necessary for platelet function and proper clotting.
3. Dysproteinemias: Abnormal levels of certain proteins in the blood, such as immunoglobulins (antibodies) or paraproteins, which can indicate underlying conditions like multiple myeloma or macroglobulinemia.
4. Hypoproteinemia: Low levels of total protein in the blood, often caused by liver disease, malnutrition, or kidney disease.
5. Hyperproteinemia: Elevated levels of total protein in the blood, which can be caused by dehydration, inflammation, or certain types of cancer.
6. Hemoglobinopathies: Genetic disorders affecting the structure and function of hemoglobin, a protein found in red blood cells that carries oxygen throughout the body. Examples include sickle cell anemia and thalassemia.
7. Disorders of complement proteins: Abnormalities in the complement system, which is a group of proteins involved in the immune response, can lead to conditions like autoimmune disorders or recurrent infections.

Treatment for blood protein disorders varies depending on the specific condition and its severity but may include medications, transfusions, or other medical interventions.

Phospholipids are a major class of lipids that consist of a hydrophilic (water-attracting) head and two hydrophobic (water-repelling) tails. The head is composed of a phosphate group, which is often bound to an organic molecule such as choline, ethanolamine, serine or inositol. The tails are made up of two fatty acid chains.

Phospholipids are a key component of cell membranes and play a crucial role in maintaining the structural integrity and function of the cell. They form a lipid bilayer, with the hydrophilic heads facing outwards and the hydrophobic tails facing inwards, creating a barrier that separates the interior of the cell from the outside environment.

Phospholipids are also involved in various cellular processes such as signal transduction, intracellular trafficking, and protein function regulation. Additionally, they serve as emulsifiers in the digestive system, helping to break down fats in the diet.

Ultracentrifugation is a medical and laboratory technique used for the separation of particles of different sizes, densities, or shapes from a mixture based on their sedimentation rates. This process involves the use of a specialized piece of equipment called an ultracentrifuge, which can generate very high centrifugal forces, much greater than those produced by a regular centrifuge.

In ultracentrifugation, a sample is placed in a special tube and spun at extremely high speeds, causing the particles within the sample to separate based on their size, shape, and density. The larger or denser particles will sediment faster and accumulate at the bottom of the tube, while smaller or less dense particles will remain suspended in the solution or sediment more slowly.

Ultracentrifugation is a valuable tool in various fields, including biochemistry, molecular biology, and virology. It can be used to purify and concentrate viruses, subcellular organelles, membrane fractions, ribosomes, DNA, and other macromolecules from complex mixtures. The technique can also provide information about the size, shape, and density of these particles, making it a crucial method for characterizing and studying their properties.

I couldn't find a medical definition for the term "butter" in and of itself, as it is not a medical term. However, butter is a common food item that can be mentioned in a medical context. Butter is a dairy product made by churning fresh or fermented cream or milk to separate the fat globules from the buttermilk. It is used as a spread, cooking fat, and ingredient in various foods.

In some cases, butter may be relevant in a medical setting due to its nutritional content. Butter is high in saturated fats and cholesterol, which can contribute to an increased risk of heart disease when consumed in excess. Therefore, individuals with certain medical conditions, such as high blood cholesterol levels or a history of heart disease, may be advised to limit their intake of butter and other high-fat dairy products.

Additionally, some people may have allergies or sensitivities to dairy products, including butter, which can cause symptoms such as hives, itching, swelling, difficulty breathing, or digestive problems. In these cases, avoiding butter and other dairy products is important for managing the allergy or sensitivity.

Fatty acids are carboxylic acids with a long aliphatic chain, which are important components of lipids and are widely distributed in living organisms. They can be classified based on the length of their carbon chain, saturation level (presence or absence of double bonds), and other structural features.

The two main types of fatty acids are:

1. Saturated fatty acids: These have no double bonds in their carbon chain and are typically solid at room temperature. Examples include palmitic acid (C16:0) and stearic acid (C18:0).
2. Unsaturated fatty acids: These contain one or more double bonds in their carbon chain and can be further classified into monounsaturated (one double bond) and polyunsaturated (two or more double bonds) fatty acids. Examples of unsaturated fatty acids include oleic acid (C18:1, monounsaturated), linoleic acid (C18:2, polyunsaturated), and alpha-linolenic acid (C18:3, polyunsaturated).

Fatty acids play crucial roles in various biological processes, such as energy storage, membrane structure, and cell signaling. Some essential fatty acids cannot be synthesized by the human body and must be obtained through dietary sources.

Lipase is an enzyme that is produced by the pancreas and found in the digestive system of most organisms. Its primary function is to catalyze the hydrolysis of fats (triglycerides) into smaller molecules, such as fatty acids and glycerol, which can then be absorbed by the intestines and utilized for energy or stored for later use.

In medical terms, lipase levels in the blood are often measured to diagnose or monitor conditions that affect the pancreas, such as pancreatitis (inflammation of the pancreas), pancreatic cancer, or cystic fibrosis. Elevated lipase levels may indicate damage to the pancreas and its ability to produce digestive enzymes.

Lipids are a broad group of organic compounds that are insoluble in water but soluble in nonpolar organic solvents. They include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E, and K), monoglycerides, diglycerides, triglycerides, and phospholipids. Lipids serve many important functions in the body, including energy storage, acting as structural components of cell membranes, and serving as signaling molecules. High levels of certain lipids, particularly cholesterol and triglycerides, in the blood are associated with an increased risk of cardiovascular disease.

The mesentery is a continuous fold of the peritoneum, the double-layered serous membrane that lines the abdominal cavity, which attaches the stomach, small intestine, large intestine (colon), and rectum to the posterior wall of the abdomen. It provides blood vessels, nerves, and lymphatic vessels to these organs.

Traditionally, the mesentery was thought to consist of separate and distinct sections along the length of the intestines. However, recent research has shown that the mesentery is a continuous organ, with a single continuous tethering point to the posterior abdominal wall. This new understanding of the anatomy of the mesentery has implications for the study of various gastrointestinal diseases and disorders.

Enterocytes are the absorptive cells that line the villi of the small intestine. They are a type of epithelial cell and play a crucial role in the absorption of nutrients from food into the bloodstream. Enterocytes have finger-like projections called microvilli on their apical surface, which increases their surface area and enhances their ability to absorb nutrients. They also contain enzymes that help digest and break down carbohydrates, proteins, and fats into smaller molecules that can be absorbed. Additionally, enterocytes play a role in the absorption of ions, water, and vitamins.

Lipid metabolism is the process by which the body breaks down and utilizes lipids (fats) for various functions, such as energy production, cell membrane formation, and hormone synthesis. This complex process involves several enzymes and pathways that regulate the digestion, absorption, transport, storage, and consumption of fats in the body.

The main types of lipids involved in metabolism include triglycerides, cholesterol, phospholipids, and fatty acids. The breakdown of these lipids begins in the digestive system, where enzymes called lipases break down dietary fats into smaller molecules called fatty acids and glycerol. These molecules are then absorbed into the bloodstream and transported to the liver, which is the main site of lipid metabolism.

In the liver, fatty acids may be further broken down for energy production or used to synthesize new lipids. Excess fatty acids may be stored as triglycerides in specialized cells called adipocytes (fat cells) for later use. Cholesterol is also metabolized in the liver, where it may be used to synthesize bile acids, steroid hormones, and other important molecules.

Disorders of lipid metabolism can lead to a range of health problems, including obesity, diabetes, cardiovascular disease, and non-alcoholic fatty liver disease (NAFLD). These conditions may be caused by genetic factors, lifestyle habits, or a combination of both. Proper diagnosis and management of lipid metabolism disorders typically involves a combination of dietary changes, exercise, and medication.

Hyperlipidemias are a group of disorders characterized by an excess of lipids (fats) or lipoproteins in the blood. These include elevated levels of cholesterol, triglycerides, or both. Hyperlipidemias can be inherited (primary) or caused by other medical conditions (secondary). They are a significant risk factor for developing cardiovascular diseases, such as atherosclerosis and coronary artery disease.

There are two main types of lipids that are commonly measured in the blood: low-density lipoprotein (LDL) cholesterol, often referred to as "bad" cholesterol, and high-density lipoprotein (HDL) cholesterol, known as "good" cholesterol. High levels of LDL cholesterol can lead to the formation of plaques in the arteries, which can narrow or block them and increase the risk of heart attack or stroke. On the other hand, high levels of HDL cholesterol are protective because they help remove LDL cholesterol from the bloodstream.

Triglycerides are another type of lipid that can be measured in the blood. Elevated triglyceride levels can also contribute to the development of cardiovascular disease, particularly when combined with high LDL cholesterol and low HDL cholesterol levels.

Hyperlipidemias are typically diagnosed through a blood test that measures the levels of various lipids and lipoproteins in the blood. Treatment may include lifestyle changes, such as following a healthy diet, getting regular exercise, losing weight, and quitting smoking, as well as medication to lower lipid levels if necessary.

Apolipoprotein B-100 (apoB-100) is a large protein component of low-density lipoprotein (LDL), also known as "bad cholesterol." It plays a crucial role in the metabolism and transport of fats and cholesterol in the body. ApoB-100 is responsible for the binding of LDL to specific receptors on cell surfaces, facilitating the uptake of lipoprotein particles by cells. Elevated levels of apoB-100 in the blood are associated with an increased risk of developing cardiovascular diseases, such as atherosclerosis and coronary artery disease.

Medical definitions generally do not include plant oils as a specific term. However, in a biological or biochemical context, plant oils, also known as vegetable oils, are defined as lipid extracts derived from various parts of plants such as seeds, fruits, and leaves. They mainly consist of triglycerides, which are esters of glycerol and three fatty acids. The composition of fatty acids can vary between different plant sources, leading to a range of physical and chemical properties that make plant oils useful for various applications in the pharmaceutical, cosmetic, and food industries. Some common examples of plant oils include olive oil, coconut oil, sunflower oil, and jojoba oil.

Metabolic clearance rate is a term used in pharmacology to describe the volume of blood or plasma from which a drug is completely removed per unit time by metabolic processes. It is a measure of the body's ability to eliminate a particular substance and is usually expressed in units of volume (e.g., milliliters or liters) per time (e.g., minutes, hours, or days).

The metabolic clearance rate can be calculated by dividing the total amount of drug eliminated by the plasma concentration of the drug and the time over which it was eliminated. It provides important information about the pharmacokinetics of a drug, including its rate of elimination and the potential for drug-drug interactions that may affect metabolism.

It is worth noting that there are different types of clearance rates, such as renal clearance rate (which refers to the removal of a drug by the kidneys) or hepatic clearance rate (which refers to the removal of a drug by the liver). Metabolic clearance rate specifically refers to the elimination of a drug through metabolic processes, which can occur in various organs throughout the body.

"Inbred strains of rats" are genetically identical rodents that have been produced through many generations of brother-sister mating. This results in a high degree of homozygosity, where the genes at any particular locus in the genome are identical in all members of the strain.

Inbred strains of rats are widely used in biomedical research because they provide a consistent and reproducible genetic background for studying various biological phenomena, including the effects of drugs, environmental factors, and genetic mutations on health and disease. Additionally, inbred strains can be used to create genetically modified models of human diseases by introducing specific mutations into their genomes.

Some commonly used inbred strains of rats include the Wistar Kyoto (WKY), Sprague-Dawley (SD), and Fischer 344 (F344) rat strains. Each strain has its own unique genetic characteristics, making them suitable for different types of research.

Apolipoprotein C-III (APOC3) is a protein that is produced in the liver and circulates in the bloodstream. It is a component of certain lipoproteins, including very low-density lipoproteins (VLDL) and chylomicrons, which are responsible for transporting fat molecules, such as triglycerides and cholesterol, throughout the body.

APOC3 plays a role in regulating the metabolism of these lipoproteins. Specifically, it inhibits the activity of an enzyme called lipoprotein lipase, which breaks down triglycerides in VLDL and chylomicrons. As a result, high levels of APOC3 can lead to an increase in triglyceride levels in the blood, which is a risk factor for cardiovascular disease.

Genetic variations in the APOC3 gene have been associated with differences in triglyceride levels and risk of cardiovascular disease. Some studies have suggested that reducing APOC3 levels through genetic editing or other means may be a promising strategy for lowering triglycerides and reducing the risk of heart disease.

Hypertriglyceridemia is a medical condition characterized by an elevated level of triglycerides in the blood. Triglycerides are a type of fat (lipid) found in your blood that can increase the risk of developing heart disease, especially when levels are very high.

In general, hypertriglyceridemia is defined as having triglyceride levels greater than 150 milligrams per deciliter (mg/dL) of blood. However, the specific definition of hypertriglyceridemia may vary depending on individual risk factors and medical history.

Hypertriglyceridemia can be caused by a variety of factors, including genetics, obesity, physical inactivity, excessive alcohol consumption, and certain medications. In some cases, it may also be a secondary consequence of other medical conditions such as diabetes or hypothyroidism. Treatment for hypertriglyceridemia typically involves lifestyle modifications such as dietary changes, increased exercise, and weight loss, as well as medication if necessary.

Apolipoprotein E (ApoE) is a protein involved in the metabolism of lipids, particularly cholesterol. It is produced primarily by the liver and is a component of several types of lipoproteins, including very low-density lipoproteins (VLDL) and high-density lipoproteins (HDL).

ApoE plays a crucial role in the transport and uptake of lipids in the body. It binds to specific receptors on cell surfaces, facilitating the delivery of lipids to cells for energy metabolism or storage. ApoE also helps to clear cholesterol from the bloodstream and is involved in the repair and maintenance of tissues.

There are three major isoforms of ApoE, designated ApoE2, ApoE3, and ApoE4, which differ from each other by only a few amino acids. These genetic variations can have significant effects on an individual's risk for developing certain diseases, particularly cardiovascular disease and Alzheimer's disease. For example, individuals who inherit the ApoE4 allele have an increased risk of developing Alzheimer's disease, while those with the ApoE2 allele may have a reduced risk.

In summary, Apolipoprotein E is a protein involved in lipid metabolism and transport, and genetic variations in this protein can influence an individual's risk for certain diseases.

Hyperlipoproteinemia Type I, also known as Familial Lipoprotein Lipase Deficiency, is a rare genetic disorder characterized by an absence or deficiency of the enzyme lipoprotein lipase. This enzyme is responsible for breaking down chylomicrons, which are large lipoprotein particles that transport dietary triglycerides from the intestines to the liver and peripheral tissues.

As a result of this deficiency, chylomicrons accumulate in the bloodstream, leading to elevated levels of triglycerides (hypertriglyceridemia) and chylomicrons (chylomiconemia). This condition can cause eruptive xanthomas, which are collections of lipid-laden foam cells that form under the skin, and recurrent pancreatitis, which is inflammation of the pancreas.

Hyperlipoproteinemia Type I is inherited in an autosomal recessive manner, meaning that an individual must inherit two copies of the mutated gene, one from each parent, to develop the condition. Treatment typically involves a low-fat diet and medications to reduce triglyceride levels.

Carbon radioisotopes are radioactive isotopes of carbon, which is an naturally occurring chemical element with the atomic number 6. The most common and stable isotope of carbon is carbon-12 (^12C), but there are also several radioactive isotopes, including carbon-11 (^11C), carbon-14 (^14C), and carbon-13 (^13C). These radioisotopes have different numbers of neutrons in their nuclei, which makes them unstable and causes them to emit radiation.

Carbon-11 has a half-life of about 20 minutes and is used in medical imaging techniques such as positron emission tomography (PET) scans. It is produced by bombarding nitrogen-14 with protons in a cyclotron.

Carbon-14, also known as radiocarbon, has a half-life of about 5730 years and is used in archaeology and geology to date organic materials. It is produced naturally in the atmosphere by cosmic rays.

Carbon-13 is stable and has a natural abundance of about 1.1% in carbon. It is not radioactive, but it can be used as a tracer in medical research and in the study of metabolic processes.

Corn oil is a type of vegetable oil that is extracted from the germ of corn (maize). It is rich in polyunsaturated fat, particularly linoleic acid, and contains about 25% saturated fat. Corn oil has a high smoke point, making it suitable for frying and baking. It is also used as an ingredient in margarine, salad dressings, and other food products. In addition to its use as a food product, corn oil is sometimes used topically on the skin as a moisturizer or emollient.

Poloxalene is not a medical term, but a chemical compound. It's an ether used as a non-ionic surfactant and emulsifying agent in the pharmaceutical industry. Poloxalene is also known for its ability to reduce the severity of bloat (gas distention) in animals, particularly in ruminants like cows, when included in their feed. However, it's not typically used as a human medication.

Electron microscopy (EM) is a type of microscopy that uses a beam of electrons to create an image of the sample being examined, resulting in much higher magnification and resolution than light microscopy. There are several types of electron microscopy, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), and reflection electron microscopy (REM).

In TEM, a beam of electrons is transmitted through a thin slice of the sample, and the electrons that pass through the sample are focused to form an image. This technique can provide detailed information about the internal structure of cells, viruses, and other biological specimens, as well as the composition and structure of materials at the atomic level.

In SEM, a beam of electrons is scanned across the surface of the sample, and the electrons that are scattered back from the surface are detected to create an image. This technique can provide information about the topography and composition of surfaces, as well as the structure of materials at the microscopic level.

REM is a variation of SEM in which the beam of electrons is reflected off the surface of the sample, rather than scattered back from it. This technique can provide information about the surface chemistry and composition of materials.

Electron microscopy has a wide range of applications in biology, medicine, and materials science, including the study of cellular structure and function, disease diagnosis, and the development of new materials and technologies.

The intestines, also known as the bowel, are a part of the digestive system that extends from the stomach to the anus. They are responsible for the further breakdown and absorption of nutrients from food, as well as the elimination of waste products. The intestines can be divided into two main sections: the small intestine and the large intestine.

The small intestine is a long, coiled tube that measures about 20 feet in length and is lined with tiny finger-like projections called villi, which increase its surface area and enhance nutrient absorption. The small intestine is where most of the digestion and absorption of nutrients takes place.

The large intestine, also known as the colon, is a wider tube that measures about 5 feet in length and is responsible for absorbing water and electrolytes from digested food, forming stool, and eliminating waste products from the body. The large intestine includes several regions, including the cecum, colon, rectum, and anus.

Together, the intestines play a critical role in maintaining overall health and well-being by ensuring that the body receives the nutrients it needs to function properly.

The small intestine is the portion of the gastrointestinal tract that extends from the pylorus of the stomach to the beginning of the large intestine (cecum). It plays a crucial role in the digestion and absorption of nutrients from food. The small intestine is divided into three parts: the duodenum, jejunum, and ileum.

1. Duodenum: This is the shortest and widest part of the small intestine, approximately 10 inches long. It receives chyme (partially digested food) from the stomach and begins the process of further digestion with the help of various enzymes and bile from the liver and pancreas.
2. Jejunum: The jejunum is the middle section, which measures about 8 feet in length. It has a large surface area due to the presence of circular folds (plicae circulares), finger-like projections called villi, and microvilli on the surface of the absorptive cells (enterocytes). These structures increase the intestinal surface area for efficient absorption of nutrients, electrolytes, and water.
3. Ileum: The ileum is the longest and final section of the small intestine, spanning about 12 feet. It continues the absorption process, mainly of vitamin B12, bile salts, and any remaining nutrients. At the end of the ileum, there is a valve called the ileocecal valve that prevents backflow of contents from the large intestine into the small intestine.

The primary function of the small intestine is to absorb the majority of nutrients, electrolytes, and water from ingested food. The mucosal lining of the small intestine contains numerous goblet cells that secrete mucus, which protects the epithelial surface and facilitates the movement of chyme through peristalsis. Additionally, the small intestine hosts a diverse community of microbiota, which contributes to various physiological functions, including digestion, immunity, and protection against pathogens.

Tritium is not a medical term, but it is a term used in the field of nuclear physics and chemistry. Tritium (symbol: T or 3H) is a radioactive isotope of hydrogen with two neutrons and one proton in its nucleus. It is also known as heavy hydrogen or superheavy hydrogen.

Tritium has a half-life of about 12.3 years, which means that it decays by emitting a low-energy beta particle (an electron) to become helium-3. Due to its radioactive nature and relatively short half-life, tritium is used in various applications, including nuclear weapons, fusion reactors, luminous paints, and medical research.

In the context of medicine, tritium may be used as a radioactive tracer in some scientific studies or medical research, but it is not a term commonly used to describe a medical condition or treatment.

In the context of medical and health sciences, particle size generally refers to the diameter or dimension of particles, which can be in the form of solid particles, droplets, or aerosols. These particles may include airborne pollutants, pharmaceutical drugs, or medical devices such as nanoparticles used in drug delivery systems.

Particle size is an important factor to consider in various medical applications because it can affect the behavior and interactions of particles with biological systems. For example, smaller particle sizes can lead to greater absorption and distribution throughout the body, while larger particle sizes may be filtered out by the body's natural defense mechanisms. Therefore, understanding particle size and its implications is crucial for optimizing the safety and efficacy of medical treatments and interventions.

Oleic acid is a monounsaturated fatty acid that is commonly found in various natural oils such as olive oil, sunflower oil, and peanut oil. Its chemical formula is cis-9-octadecenoic acid, and it is a colorless liquid at room temperature with a slight odor. Oleic acid is an important component of human diet and has been shown to have various health benefits, including reducing the risk of heart disease and improving immune function. It is also used in the manufacture of soaps, cosmetics, and other industrial products.

Biological transport refers to the movement of molecules, ions, or solutes across biological membranes or through cells in living organisms. This process is essential for maintaining homeostasis, regulating cellular functions, and enabling communication between cells. There are two main types of biological transport: passive transport and active transport.

Passive transport does not require the input of energy and includes:

1. Diffusion: The random movement of molecules from an area of high concentration to an area of low concentration until equilibrium is reached.
2. Osmosis: The diffusion of solvent molecules (usually water) across a semi-permeable membrane from an area of lower solute concentration to an area of higher solute concentration.
3. Facilitated diffusion: The assisted passage of polar or charged substances through protein channels or carriers in the cell membrane, which increases the rate of diffusion without consuming energy.

Active transport requires the input of energy (in the form of ATP) and includes:

1. Primary active transport: The direct use of ATP to move molecules against their concentration gradient, often driven by specific transport proteins called pumps.
2. Secondary active transport: The coupling of the movement of one substance down its electrochemical gradient with the uphill transport of another substance, mediated by a shared transport protein. This process is also known as co-transport or counter-transport.

Heparin is defined as a highly sulfated glycosaminoglycan (a type of polysaccharide) that is widely present in many tissues, but is most commonly derived from the mucosal tissues of mammalian lungs or intestinal mucosa. It is an anticoagulant that acts as an inhibitor of several enzymes involved in the blood coagulation cascade, primarily by activating antithrombin III which then neutralizes thrombin and other clotting factors.

Heparin is used medically to prevent and treat thromboembolic disorders such as deep vein thrombosis, pulmonary embolism, and certain types of heart attacks. It can also be used during hemodialysis, cardiac bypass surgery, and other medical procedures to prevent the formation of blood clots.

It's important to note that while heparin is a powerful anticoagulant, it does not have any fibrinolytic activity, meaning it cannot dissolve existing blood clots. Instead, it prevents new clots from forming and stops existing clots from growing larger.

Palmitic acid is a type of saturated fatty acid, which is a common component in many foods and also produced by the body. Its chemical formula is C16:0, indicating that it contains 16 carbon atoms and no double bonds. Palmitic acid is found in high concentrations in animal fats, such as butter, lard, and beef tallow, as well as in some vegetable oils, like palm kernel oil and coconut oil.

In the human body, palmitic acid can be synthesized from other substances or absorbed through the diet. It plays a crucial role in various biological processes, including energy storage, membrane structure formation, and signaling pathways regulation. However, high intake of palmitic acid has been linked to an increased risk of developing cardiovascular diseases due to its potential to raise low-density lipoprotein (LDL) cholesterol levels in the blood.

It is essential to maintain a balanced diet and consume palmitic acid-rich foods in moderation, along with regular exercise and a healthy lifestyle, to reduce the risk of chronic diseases.

Dietary cholesterol is a type of cholesterol that comes from the foods we eat. It is present in animal-derived products such as meat, poultry, dairy products, and eggs. While dietary cholesterol can contribute to an increase in blood cholesterol levels for some people, it's important to note that saturated and trans fats have a more significant impact on blood cholesterol levels than dietary cholesterol itself.

The American Heart Association recommends limiting dietary cholesterol intake to less than 300 milligrams per day for most people, and less than 200 milligrams per day for those with a history of heart disease or high cholesterol levels. However, individual responses to dietary cholesterol can vary, so it's essential to monitor blood cholesterol levels and adjust dietary habits accordingly.

Hydrolysis is a chemical process, not a medical one. However, it is relevant to medicine and biology.

Hydrolysis is the breakdown of a chemical compound due to its reaction with water, often resulting in the formation of two or more simpler compounds. In the context of physiology and medicine, hydrolysis is a crucial process in various biological reactions, such as the digestion of food molecules like proteins, carbohydrates, and fats. Enzymes called hydrolases catalyze these hydrolysis reactions to speed up the breakdown process in the body.

Lipid mobilization, also known as lipolysis, is the process by which fat cells (adipocytes) break down stored triglycerides into free fatty acids and glycerol, which can then be released into the bloodstream and used for energy by the body's cells. This process is regulated by hormones such as adrenaline, noradrenaline, glucagon, and cortisol, which activate enzymes in the fat cell that catalyze the breakdown of triglycerides. Lipid mobilization is an important physiological response to fasting, exercise, and stress, and plays a key role in maintaining energy homeostasis in the body.

Poloxamers are a type of triblock copolymer made up of a central hydrophobic chain of polyoxypropylene (poly(propylene oxide)) flanked by two hydrophilic chains of polyoxyethylene (poly(ethylene oxide)). They are amphiphilic molecules, meaning they have both hydrophilic and hydrophobic parts.

Poloxamers are often used in the pharmaceutical industry as drug delivery agents, emulsifiers, solubilizers, and stabilizers. They can form micelles in aqueous solutions above their critical micelle concentration (CMC), with the hydrophobic chains oriented toward the interior of the micelle and the hydrophilic chains on the exterior, interacting with the water molecules. This unique property allows poloxamers to solubilize drugs that are otherwise poorly soluble in water, improving their bioavailability.

Poloxamers have been studied for various medical applications, including as drug carriers for chemotherapy, diagnostic agents, and mucoadhesive materials. Some specific poloxamer compounds have been approved by the FDA for use in pharmaceutical formulations, such as Poloxamer 188 and Poloxamer 407.

In a medical context, poloxamers are not typically used as standalone treatments but rather as components of drug delivery systems or formulations.

Hyperlipoproteinemia Type III, also known as Broad Beta Disease or Remnant Hyperlipidemia, is a genetic disorder characterized by an increased level of chylomicron remnants and intermediate-density lipoproteins (IDL) in the blood. This results in elevated levels of both low-density lipoprotein (LDL), or "bad" cholesterol, and triglycerides, and decreased levels of high-density lipoprotein (HDL), or "good" cholesterol. The condition can lead to premature atherosclerosis and an increased risk for cardiovascular disease. It is caused by mutations in the APOE gene, which encodes the apolipoprotein E protein, leading to abnormal clearance of lipoproteins from the blood.

Fasting is defined in medical terms as the abstinence from food or drink for a period of time. This practice is often recommended before certain medical tests or procedures, as it helps to ensure that the results are not affected by recent eating or drinking.

In some cases, fasting may also be used as a therapeutic intervention, such as in the management of seizures or other neurological conditions. Fasting can help to lower blood sugar and insulin levels, which can have a variety of health benefits. However, it is important to note that prolonged fasting can also have negative effects on the body, including malnutrition, dehydration, and electrolyte imbalances.

Fasting is also a spiritual practice in many religions, including Christianity, Islam, Buddhism, and Hinduism. In these contexts, fasting is often seen as a way to purify the mind and body, to focus on spiritual practices, or to express devotion or mourning.

Perfusion, in medical terms, refers to the process of circulating blood through the body's organs and tissues to deliver oxygen and nutrients and remove waste products. It is a measure of the delivery of adequate blood flow to specific areas or tissues in the body. Perfusion can be assessed using various methods, including imaging techniques like computed tomography (CT) scans, magnetic resonance imaging (MRI), and perfusion scintigraphy.

Perfusion is critical for maintaining proper organ function and overall health. When perfusion is impaired or inadequate, it can lead to tissue hypoxia, acidosis, and cell death, which can result in organ dysfunction or failure. Conditions that can affect perfusion include cardiovascular disease, shock, trauma, and certain surgical procedures.

Oleic acid is a monounsaturated fatty acid that is commonly found in various natural oils such as olive oil, sunflower oil, and grapeseed oil. Its chemical formula is cis-9-octadecenoic acid, and it is a colorless liquid at room temperature. Oleic acid is an important component of human diet and has been shown to have potential health benefits, including reducing the risk of heart disease and improving immune function. It is also used in the manufacture of soaps, cosmetics, and other personal care products.

Esterification is a chemical reaction that involves the conversion of an alcohol and a carboxylic acid into an ester, typically through the removal of a molecule of water. This reaction is often catalyzed by an acid or a base, and it is a key process in organic chemistry. Esters are commonly found in nature and are responsible for the fragrances of many fruits and flowers. They are also important in the production of various industrial and consumer products, including plastics, resins, and perfumes.

Lactoferrin is a glycoprotein that belongs to the transferrin family. It is an iron-binding protein found in various exocrine secretions such as milk, tears, and saliva, as well as in neutrophils, which are a type of white blood cell involved in immune response. Lactoferrin plays a role in iron homeostasis, antimicrobial activity, and anti-inflammatory responses. It has the ability to bind free iron, which can help prevent bacterial growth by depriving them of an essential nutrient. Additionally, lactoferrin has been shown to have direct antimicrobial effects against various bacteria, viruses, and fungi. Its role in the immune system also includes modulating the activity of immune cells and regulating inflammation.

Fats, also known as lipids, are a broad group of organic compounds that are insoluble in water but soluble in nonpolar organic solvents. In the body, fats serve as a major fuel source, providing twice the amount of energy per gram compared to carbohydrates and proteins. They also play crucial roles in maintaining cell membrane structure and function, serving as precursors for various signaling molecules, and assisting in the absorption and transport of fat-soluble vitamins.

There are several types of fats:

1. Saturated fats: These fats contain no double bonds between their carbon atoms and are typically solid at room temperature. They are mainly found in animal products, such as meat, dairy, and eggs, as well as in some plant-based sources like coconut oil and palm kernel oil. Consuming high amounts of saturated fats can raise levels of harmful low-density lipoprotein (LDL) cholesterol in the blood, increasing the risk of heart disease.
2. Unsaturated fats: These fats contain one or more double bonds between their carbon atoms and are usually liquid at room temperature. They can be further divided into monounsaturated fats (one double bond) and polyunsaturated fats (two or more double bonds). Unsaturated fats, especially those from plant sources, tend to have beneficial effects on heart health by lowering LDL cholesterol levels and increasing high-density lipoprotein (HDL) cholesterol levels.
3. Trans fats: These are unsaturated fats that have undergone a process called hydrogenation, which adds hydrogen atoms to the double bonds, making them more saturated and solid at room temperature. Partially hydrogenated trans fats are commonly found in processed foods, such as baked goods, fried foods, and snack foods. Consumption of trans fats has been linked to increased risks of heart disease, stroke, and type 2 diabetes.
4. Omega-3 fatty acids: These are a specific type of polyunsaturated fat that is essential for human health. They cannot be synthesized by the body and must be obtained through diet. Omega-3 fatty acids have been shown to have numerous health benefits, including reducing inflammation, improving heart health, and supporting brain function.
5. Omega-6 fatty acids: These are another type of polyunsaturated fat that is essential for human health. They can be synthesized by the body but must also be obtained through diet. While omega-6 fatty acids are necessary for various bodily functions, excessive consumption can contribute to inflammation and other health issues. It is recommended to maintain a balanced ratio of omega-3 to omega-6 fatty acids in the diet.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

The jejunum is the middle section of the small intestine, located between the duodenum and the ileum. It is responsible for the majority of nutrient absorption that occurs in the small intestine, particularly carbohydrates, proteins, and some fats. The jejunum is characterized by its smooth muscle structure, which allows it to contract and mix food with digestive enzymes and absorb nutrients through its extensive network of finger-like projections called villi.

The jejunum is also lined with microvilli, which further increase the surface area available for absorption. Additionally, the jejunum contains numerous lymphatic vessels called lacteals, which help to absorb fats and fat-soluble vitamins into the bloodstream. Overall, the jejunum plays a critical role in the digestion and absorption of nutrients from food.

Esters are organic compounds that are formed by the reaction between an alcohol and a carboxylic acid. They are widely found in nature and are used in various industries, including the production of perfumes, flavors, and pharmaceuticals. In the context of medical definitions, esters may be mentioned in relation to their use as excipients in medications or in discussions of organic chemistry and biochemistry. Esters can also be found in various natural substances such as fats and oils, which are triesters of glycerol and fatty acids.

Fat emulsions for intravenous use are a type of parenteral nutrition solution that contain fat in the form of triglycerides, which are broken down and absorbed into the body to provide a source of energy and essential fatty acids. These emulsions are typically used in patients who are unable to consume food orally or enterally, such as those with gastrointestinal tract disorders, malabsorption syndromes, or severe injuries.

The fat emulsion is usually combined with other nutrients, such as carbohydrates and amino acids, to create a complete parenteral nutrition solution that meets the patient's nutritional needs. The emulsion is administered through a vein using a sterile technique to prevent infection.

Fat emulsions are typically made from soybean oil or a mixture of soybean and medium-chain triglyceride (MCT) oils. MCTs are more easily absorbed than long-chain triglycerides (LCTs), which are found in soybean oil, and may be used in patients with malabsorption syndromes or other conditions that affect fat absorption.

It is important to monitor patients receiving intravenous fat emulsions for signs of complications such as infection, hyperlipidemia (elevated levels of fats in the blood), and liver function abnormalities.

Linoleic acid is a type of polyunsaturated fatty acid (PUFA) that is essential for human health. It is one of the two essential fatty acids, meaning that it cannot be produced by the body and must be obtained through diet.

Linoleic acid is a member of the omega-6 fatty acid family and has a chemical structure with two double bonds at the sixth and ninth carbon atoms from the methyl end of the molecule. It is found in various plant sources, such as vegetable oils (e.g., soybean, corn, safflower, and sunflower oils), nuts, seeds, and whole grains.

Linoleic acid plays a crucial role in maintaining the fluidity and function of cell membranes, producing eicosanoids (hormone-like substances that regulate various bodily functions), and supporting skin health. However, excessive intake of linoleic acid can lead to an imbalance between omega-6 and omega-3 fatty acids, which may contribute to inflammation and chronic diseases. Therefore, it is recommended to maintain a balanced diet with appropriate amounts of both omega-6 and omega-3 fatty acids.

Apolipoprotein A-I (ApoA-I) is a major protein component of high-density lipoproteins (HDL) in human plasma. It plays a crucial role in the metabolism and transport of lipids, particularly cholesterol, within the body. ApoA-I facilitates the formation of HDL particles, which are involved in the reverse transport of cholesterol from peripheral tissues to the liver for excretion. This process is known as reverse cholesterol transport and helps maintain appropriate cholesterol levels in the body. Low levels of ApoA-I or dysfunctional ApoA-I have been associated with an increased risk of developing cardiovascular diseases.

... to the nascent chylomicron and, thus, converts it to a mature chylomicron (often referred to simply as "chylomicron"). APOC2 is ... becomes a chylomicron remnant, now only 30-50 nm. ApoB48 and APOE are important to identify the chylomicron remnant in the ... resulting in mature chylomicrons. Mature chylomicrons are secreted through the basolateral membrane into the lacteals, where ... From there, the chylomicrons supply the tissue with fat absorbed from the diet. It is important to note that, unlike digested ...
Without functional chylomicrons, certain fat-soluble vitamins such as vitamin D and vitamin E cannot be absorbed. Chylomicrons ... These proteins are critical for release of chylomicrons in the body. Chylomicron retention disease is an autosomal homozygous ... The pre-chylomicrons are then packaged into PCTV to be transported to the Golgi apparatus for additional maturation prior to ... In chylomicron retention disease, the PCTV vesicles are competent for budding from the ER membrane but are defective for fusion ...
Kuksis A (2000). "Biochemistry of Glycerolipids and Formation of Chylomicrons". In Christophe AB, DeVriese S (eds.). Fat ... while long-chain fatty acids are packed into chylomicrons, enter lymphatic capillaries, then transfer to the blood at the ...
CYBB Chylomicron retention disease; 246700; SAR1B Ciliary dyskinesia, primary, 1, with or without situs inversus; 244400; DNAI1 ...
The hydrolyzed chylomicrons are now called chylomicron remnants. The chylomicron remnants continue circulating the bloodstream ... The chylomicron at this stage is then considered mature. Via apolipoprotein C-II, mature chylomicrons activate lipoprotein ... Chylomicrons carry triglycerides (fat) from the intestines to the liver, to skeletal muscle, and to adipose tissue. Very-low- ... Then these lipids are assembled with apolipoprotein B-48 into nascent chylomicrons. These particles are then secreted into the ...
"Incorporation of carotenoids from paprika oleoresin into human chylomicrons". Br. J. Nutr. 89 (6): 787-93. doi:10.1079/ ...
"Incorporation of carotenoids from paprika oleoresin into human chylomicrons". British Journal of Nutrition. 89 (6): 787-793. ...
Julve, Josep; Martín-Campos, Jesús M.; Escolà-Gil, Joan Carles; Blanco-Vaca, Francisco (2016). "Chylomicrons: Advances in ...
VLDL is one of the five major groups of lipoproteins (chylomicrons, VLDL, intermediate-density lipoprotein, low-density ... VLDL transports endogenous products, whereas chylomicrons transport exogenous (dietary) products. In the early 2010s both the ...
The lipids in the chyle are colloidally suspended in chylomicrons. A chyle fistula occurs when defect(s) of lymphatic vessel(s ...
Since there is no or little assimilation of chylomicrons, their levels in plasma remains low.[citation needed] The inability to ... Low levels of plasma chylomicron are also characteristic.[citation needed] There is an absence of apolipoprotein B. On ... January 2013). "Novel mutations in SAR1B and MTTP genes in Tunisian children with chylomicron retention disease and ... September 2018). "Efficacy of two vitamin E formulations in patients with abetalipoproteinemia and chylomicron retention ...
The triglycerides in chylomicrons are hydrolyzed by lipoprotein lipase (LPL) along the luminal surface of capillaries, mainly ... GPIHBP1 is a capillary endothelial cell protein that provides a platform for LPL-mediated processing of chylomicrons. GRCh38: ... Dietary fats are packaged by intestine into triglyceride-rich lipoproteins called chylomicrons. ... "The Acidic Domain of GPIHBP1 is Important for the Binding of Lipoprotein Lipase and Chylomicrons". Journal of Biological ...
... assembly and secretion of chylomicrons. These chylomicrons transport dietary lipids to tissues while the remaining chylomicrons ... ApoB 48 is a unique protein to chylomicrons from the small intestine. After most of the lipids in the chylomicron have been ... Apolipoprotein B is the primary apolipoprotein of chylomicrons, VLDL, Lp(a), IDL, and LDL particles (LDL-commonly known as "bad ... Intestinal proteins containing ApoB48 are metabolized to chylomicron remnant particles which are taken up by remnant receptors ...
At this point, the fats are in the bloodstream in the form of chylomicrons. Once in the blood, chylomicrons are subject to ... now referred to as a chylomicron remnant) can be taken up by the liver. From the liver, the fat released from chylomicron ... These chylomicrons then pass into the lacteals, forming a milky substance known as chyle. The lacteals merge to form larger ... The triglyceride is then combined with phospholipids, cholesterol ester, and apolipoprotein B48 to form chylomicrons. ...
It is a component of several lipoprotein fractions including VLDL, HDL, chylomicrons. It is believed that apoA-V affects ... APOA5 is associated predominantly with TG-rich lipoproteins (chylomicrons and VLDL) and has also been detected on HDL particles ... and chylomicrons, and circulates at very low concentrations compared with other apolipoproteins". Clinical Chemistry. 51 (2): ...
The chylomicrons are small enough to pass through the enterocyte villi and into their lymph capillaries called lacteals. A ... From this breakdown, smaller particles of emulsified fats called chylomicrons are produced. There are also digestive cells ... milky fluid called chyle, consisting mainly of the emulsified fats of the chylomicrons, results from the absorbed mix with the ...
Hofmann AF (Sep 1960). "Exchange of iodine-131-labeled chylomicron protein in vitro". Am. J. Physiol. 199 (3): 433-6. doi: ... His initial publications in 1960 characterized his future research: Exchange of iodine-131-labeled chylomicron protein in vitro ...
By reducing the cholesterol content in chylomicrons and chylomicron remnants, cholesterol absorption inhibitors effectively ... These chylomicrons are then secreted into the lymphatics and circulated to the liver. These cholesterol particles are then ... Once absorbed by the enterocyte, cholesterol is reassembled into intestinal lipoproteins called chylomicrons. ... thereby reducing the incorporation of cholesterol esters into chylomicron particles. ...
... triglycerides are combined with vitamins and cholesterol to form chylomicrons. Chylomicrons travel from the intestine into the ... Enzymatic catalysis of chylomicrons by lipases in the bloodstream enables the uptake of lipids and fatty acids by cells. In ...
May 2005). "CD36 deficiency impairs intestinal lipid secretion and clearance of chylomicrons from the blood". The Journal of ...
... forming a large transporter particle called chylomicron. The chylomicron enters a lymphatic capillary, then it is transported ... The chylomicrons are ultimately taken up by liver hepatocytes via interaction between apolipoprotein E and the LDL receptor or ... In the liver, chylomicron particles release triglycerides and some cholesterol. The liver converts unburned food metabolites ... In lipid digestion, cholesterol is packed into chylomicrons in the small intestine, which are delivered to the portal vein and ...
After a meal, roughly two-thirds of the chylomicrons are taken up by the liver with the remainder delivered to peripheral ... Absorbed β-carotene is either incorporated as such into chylomicrons or first converted to retinal and then retinol, bound to ... Peripheral tissues also can convert chylomicron β-carotene to retinol. The capacity to store retinol in the liver means that ... Hepatocytes take up the lipid-rich chylomicrons, bind retinol to retinol-binding protein 4 (RBP4), and transfer the retinol- ...
"Intestinal alkaline phosphatase release is not associated with chylomicron formation". American Journal of Physiology. ...
Chylomicrons are degraded, VLDLs are converted to LDLs, and LDLs are converted to HDL. This is accompanied by a slight increase ...
It is a water-soluble enzyme that hydrolyzes triglycerides in lipoproteins, such as those found in chylomicrons and very low- ... Beisiegel U, Weber W, Bengtsson-Olivecrona G (October 1991). "Lipoprotein lipase enhances the binding of chylomicrons to low ... a carboxylate It is also involved in promoting the cellular uptake of chylomicron remnants, cholesterol-rich lipoproteins, and ... high-density lipoprotein-binding protein 1 plays a critical role in the lipolytic processing of chylomicrons". Cell Metabolism ...
The thoracic duct empties the chylomicrons into the bloodstream via the left subclavian vein. At this point the chylomicrons ... They are taken in through the intestine in chylomicrons, but also exist in very low density lipoproteins (VLDL) and low density ... The triglycerides are coated with cholesterol and protein (protein coat) into a compound called a chylomicron. From within the ... cell, the chylomicron is released into a lymphatic capillary called a lacteal, which merges into larger lymphatic vessels. It ...
A third form, chylomicron retention disease (CRD), is associated with SARA2. Typically in hypobetalipoproteinemia, plasma ...
... A-IV (apoA4) is present in chylomicrons, very-low-density lipoproteins (VLDL), and HDL. It is thought to act ... primarily in reverse cholesterol transport and intestinal lipid absorption via chylomicron assembly and secretion. ApoA-IV ...
Chylomicrons are one sub-group of lipoproteins which carry the digested lipids from small intestine to the rest of the body. ... Chylomicrons will travel through the bloodstream to enter adipose and other tissues in the body. Due to the hydrophobic nature ... Once the chylomicrons (or other lipoproteins) travel through the tissues, these particles will be broken down by lipoprotein ... In the cytosol of epithelial cells, triglycerides and cholesterol are packaged into bigger particles called chylomicrons which ...
Symptoms are caused by an increase in the level of chylomicron in the retinal circulation. Though visual acuity is not affected ... In primary hyperlipidaemia, LR occurs only in patients with increased chylomicron levels. Lipaemia retinalis occurs commonly ...
... to the nascent chylomicron and, thus, converts it to a mature chylomicron (often referred to simply as "chylomicron"). APOC2 is ... becomes a chylomicron remnant, now only 30-50 nm. ApoB48 and APOE are important to identify the chylomicron remnant in the ... resulting in mature chylomicrons. Mature chylomicrons are secreted through the basolateral membrane into the lacteals, where ... From there, the chylomicrons supply the tissue with fat absorbed from the diet. It is important to note that, unlike digested ...
Chylomicron retention disease is an inherited disorder that impairs the normal absorption of fats, cholesterol, and certain ... Chylomicron Retention Disease. 2022 Mar 24. In: Adam MP, Feldman J, Mirzaa GM, Pagon RA, Wallace SE, Bean LJH, Gripp KW, ... Mutations in a gene called SAR1B cause chylomicron retention disease. The SAR1B gene provides instructions for making a protein ... Chylomicrons are needed to absorb fat-soluble vitamins and carry fats and cholesterol from the small intestine into the ...
"Chylomicrons" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus, MeSH (Medical Subject ... Intestinal scavenger receptor class B type I as a novel regulator of chylomicron production in healthy and diet-induced obese ... This graph shows the total number of publications written about "Chylomicrons" by people in Harvard Catalyst Profiles by year, ... Below are the most recent publications written about "Chylomicrons" by people in Profiles. ...
... , 3.5 mL, 90,000 rpm, 122,000 x g. Product No:341260. ACR-90 Chylomicron Rotor, Aluminum, Anodized ...
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Chylomicron is part of lipoprotein. When present in excess, leads to change of serum color. ... Functions of chylomicron:. *Chylomicron is responsible for transporting the dietary fats from the small intestine to the tissue ... Chylomicron. Sample for Chylomicron. *The best sample is serum after 10 to 12 hours of fasting. ... Definition of chylomicron. *Chylomicron is in particulate form of lipoprotein, which is responsible for transporting exogenous ...
The main difference between chylomicrons and micelles is that chylomicrons are lipoproteins having a core of triglycerides and ... Moreover, chylomicrons are the largest of the lipoproteins. They are synthesized in the intestine. Chylomicrons are made in the ... What are Chylomicrons. Chylomicrons are lipoproteins having a core of triglycerides and cholesterols and a coat of ... Difference Between Chylomicrons and Micelles. Definition. Chylomicrons are lipoproteins having a core of triglycerides and ...
Chylomicron and VLDL metabolism. Any disturbance that causes increased synthesis of chylomicrons and/or VLDLs or decreased ... Lipoprotein lipase (LPL) releases free fatty acids (FFAs) from chylomicrons (chylo) and produces chylomicron remnants that are ... Lipoprotein lipase (LPL) releases free fatty acids (FFAs) from chylomicrons (chylo) and produces chylomicron remnants that are ... a structural apolipoprotein that is not removed during catabolism of the chylomicron. Chylomicrons enter the plasma via the ...
Model of Chicken Chorioallantoic Membranes in Surrogate Shells Revealed the Pro-angiogenesis Effects of Chylomicrons Share ... Model of Chicken Chorioallantoic Membranes in Surrogate Shells Revealed the Pro-angiogenesis Effects of Chylomicrons ...
Molecular structure of lipoproteins of the blood: LDL, HDL, chylomicron, VLDL and their components cholesterol, cholesterol ... Lipoproteins of the blood, LDL, HDL, chylomicron, VLDL. Molecular structure of lipoproteins of the blood: LDL, HDL, chylomicron ...
Chylomicrons fill knowledge gap 29-Nov-2004. The knowledge gap between why people with low bad cholesterol levels are still ...
Familial Lipoprotein Lipase Deficiency and Related Disorders of Chylomicron Metabolism. In Stanbury J.B., et al. (eds.): The ... Drug therapy is not indicated for patients with Type I hyperlipoproteinemia, who have elevations of chylomicrons and plasma ...
3H]TG-labeled chylomicrons.. A male Wistar rat was orally given a mixture of 0.5 ml olive oil with 1 mCi of [9,10(n)-3H]oleic ... Chylomicrons and lipid emulsions were labeled with [3H]triolein, injected into mice, and appearance in plasma of [3H]oleic acid ... In accordance with the chylomicron data, 89% of the label had to enter the plasma FA compartment to obtain a good fit. It was ... Kinetic behavior of TG and FA tracers after a bolus injection of a mixture of rat chylomicrons labeled with [3H]triolein and ...
They typically have high chylomicrons, not only high VLDL particles.. Then theres the lower end of the spectrum, 150 and above ...
Lymphatic transport of high-density lipoproteins and chylomicrons Gwendalyn J. Randolph et al. ...
Chylomicrons. Definition. lipoprotein, mostly tg from small intestine to circulation, for ATP in muscle cells. ...
Chylomicrons, Estrogens, Nephrotic Syndrome, Vitamin D, Dietary Carbohydrates, Diet, Fat-Restricted, Tamoxifen, Retinoids, ... While VLDL is believed to be atherogenic, similar to LDL, elevated chylomicrons impart an increased risk of acute pancreatitis ... versus whereas in the latter they are carried in VLDL and chylomicrons. ...
Postprandial hyperlipidemia and FFA spillover from chylomicrons worsen the situation [27,50]. Chylomicrons and triglyceride- ... Under postprandial conditions, an important source of FFA is due to the increased spillover from chylomicrons [27]. The ...
Randolph, G. J., & Miller, N. E. (2014). Lymphatic transport of high-density lipoproteins and chylomicrons. The Journal of ... Lymphatic transport of high-density lipoproteins and chylomicrons. The Journal of Clinical Investigation, 124(3), 929-935. http ...
How is the fetal gut colonized? Please see my new article here describing one mechanism where maternal chylomicrons reach the ... I think yet again he misunderstood the paper he cited that said that an apolipoprotein in chylomicrons antagonizes S. Aureus; ... and given the structure of chylomicrons, I struggle to see how a bacterium could fit inside one, or how it would get in there ... perhaps he thinks "antagonizes" means "carries". Since the very largest chylomicron is 1,200 nanometers in diameter, while most ...
The scientists want to influence the size and composition of chylomicrons, because these characteristics dictate the fate of ... There they are reassembled into chylomicrons and absorbed into blood circulation through the lymph system. ... but introducing food-grade nano-emulsion systems that can influence the nature of mixed micelles as well as chylomicrons," says ... to mixed micelles and finally to chylomicrons. To start this process, digestion physiochemically disassembles nano-emulsion ...
Chylomicron-like lipid emulsions, resembling chylomicrons in composition, size and metabolism were prepared in the presence of ... The chylomicron-like emulsions containing Aβ were then injected into a lateral ear vein of conscious rabbits and blood sampled ... The incorporation and metabolism of amyloid-β into chylomicron-like lipid emulsions ...
Fat in the diet enables optimal chylomicron formation [21,22]. According to the study by Leung et al., carrying one of the two ... These are packaged with other dietary lipids into chylomicrons and then secreted into the lymphatic system. ...
Chylomicron metabolism is markedly altered in systemic lupus erythematosus. Arthritis Rheum 2000;43:1033-40. * Cited Here , ...
Subsequently, the vitamin D is transported in the chylomicrons via lymph to the circulation [89]. The more polar metabolite 25( ...
Optimized, fast through-put UHPLC-DAD based method for carotenoid quantification in spinach, serum, chylomicrons and faeces. ...
Lymph contains chylomicrons from digestion, as well as hormones secreted by enteroendocrine cells. In addition, there is ...
Dietary triglycerides are delivered to the liver in the form of chylomicrons. In addition, dietary calories stored in adipose ...
Chylomicrons may have still been present in the sera, exaggerating triglyceride levels. In that case, the true rate of ...
  • While circulating in blood, chylomicrons exchange components with high-density lipoproteins (HDL). (wikipedia.org)
  • The main difference between chylomicrons and micelles is that chylomicrons are lipoproteins having a core of t riglycerides and cholesterols and a coat made of apolipoproteins and phospholipids , whereas micelles are globules of lipid molecules that are arranged in a spherical form in an aqueous solution. (pediaa.com)
  • Chylomicrons are lipoproteins having a core of triglycerides and cholesterols and a coat of apolipoproteins and phospholipids. (pediaa.com)
  • Moreover, chylomicrons are the largest of the lipoproteins. (pediaa.com)
  • They are carried on 4 types of lipoproteins: chylomicrons, low-density lipoproteins (LDL), very-low-density lipoproteins (VLDL) and high-density lipoproteins (HDL). (who.int)
  • Monolayer membranes include the outer monolayer phospholipid surface of intracellular lipid droplets of triglycerides and various lipoproteins including HDL, LDL, VLDL, and chylomicrons. (nih.gov)
  • It is produced in the liver and while a chylomicron is also a form of lipoprotein, there are 4 other types of lipoproteins which play an important role in fat metabolism, transport and utilization. (healthhype.com)
  • This gene encodes s receptor in the endoplasmic reticulum, which plays a role in the export of large pre-chylomicrons and pre-very low density lipoproteins (pre-VLDLs). (nih.gov)
  • Once absorbed into enterocytes, they are reassembled into TGs and packaged with cholesterol into chylomicrons, the largest lipoproteins. (msdmanuals.com)
  • In the former, the excess TGs are carried in very low-density lipoprotein (VLDL) versus whereas in the latter they are carried in VLDL and chylomicrons. (acc.org)
  • While VLDL is believed to be atherogenic, similar to LDL, elevated chylomicrons impart an increased risk of acute pancreatitis. (acc.org)
  • APOE is also involved in the formation of chylomicrons and VLDL and affects the activity of other lipid metabolism-associated proteins and enzymes, such as hepatic lipase and lipoprotein lipase. (dovepress.com)
  • APOE is an integral component of chylomicrons, VLDL, and HDL in the peripheral system ( Table 1 ). (dovepress.com)
  • These triglycerides, along with phospholipids and cholesterol, are added to apolipoprotein B48 to form immature chylomicrons. (wikipedia.org)
  • The triglycerides are then combined with phospholipids, cholesteryl esters, and apolipoprotein B48 (ApoB48) to form a nascent chylomicron. (wikipedia.org)
  • Nascent chylomicrons are composed primarily of triglycerides (85%) and contain some cholesterol and cholesteryl esters. (wikipedia.org)
  • Chylomicron is in particulate form of lipoprotein, which is responsible for transporting exogenous cholesterol and triglycerides from the small intestine to the adipose tissue after the meal. (labpedia.net)
  • Chylomicron is a spherical particle with a core of triglycerides surrounded by a monolayer of phospholipids, cholesterol, and lipoprotein. (labpedia.net)
  • Chylomicrons also play a crucial role in the transportation of dietary triglycerides to skeletal muscles and adipose tissue. (pediaa.com)
  • Thus, chylomicrons not only aid in the distribution of dietary triglycerides but also assist in preventing their accumulation in the body. (pediaa.com)
  • Type I is a rare disorder characterized by severe elevations in chylomicrons and extremely elevated triglycerides, always reaching well above 1000 mg/dL and not infrequently rising as high as 10,000 mg/dL or more. (medscape.com)
  • The fatty acids will most likely be re-esterified to triglycerides after absorption and transported via chylomicrons. (europa.eu)
  • These chylomicrons do not only carry cholesterol but it also carries other types of fats like triglycerides and phospholipids. (healthhype.com)
  • It is important to note that, unlike digested carbohydrates (in the form of monosaccharides) and proteins (in the form of amino acids), digested lipids (in the form of chylomicrons) bypass the hepatic portal system, avoiding first pass metabolism. (wikipedia.org)
  • When a large portion of the triglyceride core has been hydrolyzed, chylomicron remnants are formed and are taken up by the liver, thereby also transferring dietary fat to the liver. (wikipedia.org)
  • Cholesterol-rich chylomicron remnants then circulate back to the liver, where they are cleared in a process mediated by apoprotein E (apo E). (msdmanuals.com)
  • SAR1B gene mutations cause the retention of chylomicrons within enterocytes and prevent their release into the bloodstream. (medlineplus.gov)
  • These chylomicrons exit the enterocytes by exocytosis. (pediaa.com)
  • Chylomicrons transport dietary TGs and cholesterol from within enterocytes through lymphatics into the circulation. (msdmanuals.com)
  • Differential associations between plasma concentrations of insulin and glucose and intestinal expression of key genes involved in chylomicron metabolism. (harvard.edu)
  • Chylomicron-like lipid emulsions, resembling chylomicrons in composition, size and metabolism were prepared in the presence of [125 I]Aβ1-40. (iospress.com)
  • Chylomicrons transport lipids absorbed from the intestine to adipose, cardiac, and skeletal muscle tissue, where their triglyceride components are hydrolyzed by the activity of the lipoprotein lipase, allowing the released free fatty acids to be absorbed by the tissues. (wikipedia.org)
  • The adipose tissue and liver break down these chylomicrons by the action of the enzyme lipoprotein lipase. (healthhype.com)
  • In the capillaries of adipose and muscle tissue, apoprotein C-II (apo C-II) on the chylomicron activates endothelial lipoprotein lipase (LPL) to convert 90% of chylomicron triglyceride to fatty acids and glycerol, which are taken up by adipocytes and muscle cells for energy use or storage. (msdmanuals.com)
  • Chylomicron retention disease is an inherited disorder that impairs the normal absorption of fats, cholesterol, and certain vitamins from food. (medlineplus.gov)
  • Chylomicrons are needed to absorb fat-soluble vitamins and carry fats and cholesterol from the small intestine into the bloodstream . (medlineplus.gov)
  • When cholesterol is absorbed from the gut, it is transported in the form of a chylomicron from the intestinal lacteals, through the lymphatic system and emptied into the blood stream. (healthhype.com)
  • Once triglyceride stores are distributed, the chylomicron returns APOC2 to the HDL (but keeps APOE), and, thus, becomes a chylomicron remnant, now only 30-50 nm. (wikipedia.org)
  • Triglyceride is the major component of the chylomicron. (labpedia.net)
  • Chylomicrons and lipid emulsions were labeled with [ 3 H]triolein, injected into mice, and appearance in plasma of [ 3 H]oleic acid was estimated, either through a steady-state approach or by compartmental modeling. (diabetesjournals.org)
  • The features of chylomicron retention disease primarily affect the gastrointestinal system and nervous system. (medlineplus.gov)
  • Chylomicron retention disease begins in infancy or early childhood. (medlineplus.gov)
  • Other features of chylomicron retention disease develop later in childhood and often impair the function of the nervous system. (medlineplus.gov)
  • Chylomicron retention disease is a rare condition with approximately 50 cases described worldwide. (medlineplus.gov)
  • Mutations in a gene called SAR1B cause chylomicron retention disease. (medlineplus.gov)
  • Impaired chylomicron transport causes severely decreased absorption (malabsorption) of dietary fats and fat-soluble vitamins, leading to nutritional and developmental problems in people with chylomicron retention disease. (medlineplus.gov)
  • Charcosset M, Sassolas A, Peretti N, Roy CC, Deslandres C, Sinnett D, Levy E, Lachaux A. Anderson or chylomicron retention disease: molecular impact of five mutations in the SAR1B gene on the structure and the functionality of Sar1b protein. (medlineplus.gov)
  • Chylomicron forms in the endoplasmic reticulum of intestinal epithelial cells. (labpedia.net)
  • Chylomicrons are made in the endoplasmic reticulum and later processed in the Golgi complex. (pediaa.com)
  • ApoB48 and APOE are important to identify the chylomicron remnant in the liver for endocytosis and breakdown. (wikipedia.org)
  • The remaining fat molecules are absorbed by chylomicrons, which then transport them to the liver. (pediaa.com)
  • Immature chylomicrons are transported from the smooth ER to the Golgi apparatus via SAR1B proteins, where they are processed, resulting in mature chylomicrons. (wikipedia.org)
  • Hesse D, Jaschke A, Chung B, Schurmann A. Trans-Golgi proteins participate in the control of lipid droplet and chylomicron formation. (medlineplus.gov)
  • The scientists want to influence the size and composition of chylomicrons, because these characteristics dictate the fate of nutraceuticals encapsulated in the chylomicrons. (eurekalert.org)
  • Chylomicron is responsible for transporting the dietary fats from the small intestine to the tissue-like adipose, cardiac and skeletal muscles. (labpedia.net)
  • Chylomicron transport fats to adipose tissue and muscles. (labpedia.net)
  • Chylomicrons transport hydrophobic lipids from the small intestine to adipose, skeletal, and cardiac muscle tissue, while micelles help in the absorption of lipids and fat-soluble vitamins such as vitamins A, K, D, and E. (pediaa.com)
  • Intestinal scavenger receptor class B type I as a novel regulator of chylomicron production in healthy and diet-induced obese states. (harvard.edu)
  • The three stages of the chylomicron are nascent, mature, and remnant. (wikipedia.org)
  • Micelles and chylomicrons are two such globules that take the shape of a sphere. (pediaa.com)
  • Both chylomicrons and micelles are fat globules. (pediaa.com)
  • In brief, chylomicrons and micelles are fat globules having a hydrophobic core and a hydrophilic coat. (pediaa.com)
  • Specifically, using both cell culture and animal models, Xiao and colleagues will design lipid nanoparticles at three stages: From nano-emulsion droplets containing nutraceuticals, to mixed micelles and finally to chylomicrons. (eurekalert.org)
  • We're basically utilizing what already happens in our bodies all the time, but introducing food-grade nano-emulsion systems that can influence the nature of mixed micelles as well as chylomicrons," says Xiao. (eurekalert.org)
  • The SAR1B gene provides instructions for making a protein that is needed for the transport of molecules called chylomicrons. (medlineplus.gov)
  • Large chylomicrons have a diameter of about 1000 nm, while the smallest particles have a diameter of 75 nm to 200 nm. (pediaa.com)
  • The Airfuge ® Air-Driven ultracentrifuge offers a simple, rapid method for removing chylomicrons (fat particles in lipemic samples) for accurate lipemic clarification results. (beckman.com)
  • Mature chylomicrons are secreted through the basolateral membrane into the lacteals, where they join lymph to become chyle. (wikipedia.org)
  • The hyperchylomicronemia syndrome is a disorder characterized by extreme hypertriglyceridemia, the presence of chylomicrons, and one or more of the following clinical manifestations: eruptive xanthomas, lipaemia retinalis, hepatosplenomegaly, recurrent abdominal pain, and/ or acute pancreatitis. (wikipedia.org)
  • Chylomicrons" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (harvard.edu)
  • There they are reassembled into chylomicrons and absorbed into blood circulation through the lymph system. (eurekalert.org)
  • The chylomicron-like emulsions containing Aβ were then injected into a lateral ear vein of conscious rabbits and blood sampled at regular intervals up to … 30 mins. (iospress.com)
  • The rationale behind fasting is to eliminate chylomicrons in the blood. (medscape.com)
  • Apolipoprotein (apo) B-48 is important for the formation of chylomicrons. (labpedia.net)
  • Chylomicron provides energy to the cardiac muscles and skeletal muscles. (labpedia.net)
  • Apo E also plays an important role in the formation of very low density lipoprotein and chylomicrons. (thermofisher.com)
  • This graph shows the total number of publications written about "Chylomicrons" by people in Harvard Catalyst Profiles by year, and whether "Chylomicrons" was a major or minor topic of these publication. (harvard.edu)
  • What is a major component of chylomicron? (labpedia.net)
  • What is the main function of the chylomicron? (labpedia.net)
  • Below are the most recent publications written about "Chylomicrons" by people in Profiles. (harvard.edu)