Where is lipoprotein found?

lipoprotein, any member of a group of substances containing both lipid (fat) and protein. They occur in both soluble complexes—as in egg yolk and mammalian blood plasma—and insoluble ones, as in cell membranes.

A lipoprotein (a) test measures the level of lipoprotein (a) in your blood. Lipoproteins are substances made of protein and fat that carry cholesterol through your bloodstream. There are two main types of cholesterol: High-density lipoprotein (HDL), or “good” cholesterol.

Plasma lipoproteins are macromolecular assemblies of proteins and lipids found in the blood. The lipid components of lipoproteins are amphipathic lipids such as phospholipids (PLs), and unesterified cholesterols (UCs) and hydrophobic lipids such as cholesteryl esters (CEs) and triglycerides (TGs).

Lipoproteins are synthesized in the liver and they obtain their mature form following interaction with enzymes that are present in the circulation. Lipoprotein-derived fatty acids are released by lipoprotein lipase and are then taken up by cardiomyocytes either passively or via fatty acid receptors, such as CD36.

Lipoproteins are complex aggregates of lipids and proteins that render endogenous lipids compatible with the aqueous environment of body fluids (Brown, 2007). The major physiological role of lipoproteins is to transport water-insoluble lipids from their point of origin to their respective destinations.

The primary function of lipoproteins is the transportation and delivery of fatty acids, triacylglycerol, and cholesterol to and from target cells in many organs.

Lipoprotein(a) [Lp(a)] is a highly atherogenic lipoprotein that is under strong genetic control by the LPA gene locus. Genetic variants including a highly polymorphic copy number variation of the so called kringle IV repeats at this locus have a pronounced influence on Lp(a) concentrations.

Chylomicrons are large triglyceride-rich lipoproteins produced in enterocytes from dietary lipids—namely, fatty acids, and cholesterol. Chylomicrons are composed of a main central lipid core that consists primarily of triglycerides, however like other lipoproteins, they carry esterified cholesterol and phospholipids.

Chylomicrons, the largest and most lipid-rich particles, containing principally TGs, are secreted by the intestine and are abundant in plasma only after a meal. Very low density LPs (VLDLs), which are also rich in TG, are secreted mainly by the liver, although some are also secreted by the intestine.

Lipoproteins are special particles made up of droplets of fats surrounded by a single layer of phospholipid molecules. Phospholipids are molecules of fats which are attached to a phosphorus-containing group. They are distinctive in being amphipathic, which means they have both polar and non-polar ends.

Many enzymes, transporters, structural proteins, antigens, adhesins, and toxins are lipoproteins. Examples include plasma lipoprotein particles (HDL, LDL, IDL, VLDL and chylomicrons). Subgroups of these plasma particles are primary drivers or modulators of atherosclerosis.

The endogenous lipoprotein pathway begins in the liver with the formation of VLDL. The triglycerides carried in VLDL are metabolized in muscle and adipose tissue by lipoprotein lipase releasing free fatty acids and IDL are formed.

Lipoproteins are spherical particles that carry lipids, or fats, in the body. These particles contain both lipids and proteins. People get lipids from their diet. The body can also make its own lipids, which are known as endogenous lipids.

Chylomicron: A small fat globule composed of protein and lipid (fat). Chylomicrons are found in the blood and lymphatic fluid where they serve to transport fat from its port of entry in the intestine to the liver and to adipose (fat) tissue.

There are four major classes of circulating lipoproteins, each with its own characteristic protein and lipid composition. They are chylomicrons, very low-density lipoproteins (VLDL), low-density lipoproteins (LDL), and high-density lipoproteins (HDL).

HDL (high-density lipoprotein), or “good” cholesterol, absorbs cholesterol and carries it back to the liver. The liver then flushes it from the body. High levels of HDL cholesterol can lower your risk for heart disease and stroke.

In lipoproteins Cholesterol is minimally soluble in water; it cannot dissolve and travel in the water-based bloodstream. Instead, it is transported in the bloodstream by lipoproteins that are water-soluble and carry cholesterol and triglycerides internally.

Lp(a) is common in the general population, but there are racial differences that may explain why some people are at higher risk of heart disease. South Asians have the highest prevalence, with 35 percent of their population having Lp(a) greater than 50 milligrams per deciliter, followed by Africans at 30 percent.

Besides genetics, Lipoprotein (a) levels may result from increased intake of some types of fats, and some medical conditions. Treatment of elevated Lipoprotein (a) is based on a person’s risk of heart attack or stroke.

Most people have Lp(a) levels in the range of under 5 to 29 milligrams per deciliter (mg/dL), which roughly equals under 13 to 73 nanomoles per liter (nmol/L.

Very-low-density lipoprotein (VLDL) cholesterol is produced in the liver and released into the bloodstream to supply body tissues with a type of fat (triglycerides). There are several types of cholesterol, each made up of lipoproteins and fats.

Generally, lipoproteins are carrier molecules, which transport hydrophobic molecules inside their core, especially lipids such as triglycerides and cholesterol esters. Moreover, chylomicrons are the form of lipoproteins that contain the highest amount of triglycerides.

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.

Cholesterol and other fats are carried in your bloodstream as spherical particles called lipoproteins. The two most commonly known lipoproteins are low-density lipoproteins (LDL) and high-density lipoproteins (HDL).

Made in your liver and then entering your bloodstream, lipoprotein(a) has been shown to build up under the inner lining of arteries. This buildup may contribute to the development of atherosclerosis—the formation of fatty plaques in your arteries that can lead to heart disease, heart attack, and stroke.

In your brain. The brain is cholesterol-rich on purpose—because it needs large amounts of cholesterol to function properly.

LDL , the “bad” cholesterol, transports cholesterol particles throughout your body. LDL cholesterol builds up in the walls of your arteries, making them hard and narrow. High-density lipoprotein (HDL). HDL , the “good” cholesterol, picks up excess cholesterol and takes it back to your liver.

To achieve Lp(a) reduction, one evidence-based approach is to initiate therapy with low-dose aspirin and extended-release niacin, titrated from 0.5 g up to 2 g over several weeks.