Lipoproteins play critical roles in lipid metabolism, facilitating the transport of hydrophobic lipids, such as cholesterol and triglycerides, through the aqueous environment of the bloodstream and interstitial fluid. These particles consist of a core of lipids surrounded by a shell of proteins and some phospholipids. The various types of lipoproteins differ in their lipid and protein composition, density, and functions. Lipoproteins are classified based upon their density, determined by the proportion of lipids to proteins. The major classes of lipoproteins include chylomicrons, very-low-density lipoproteins (VLDL), low-density lipoproteins (LDL), and high-density lipoproteins (HDL). Chylomicrons are the largest and least dense lipoproteins, formed in the intestinal epithelial cells after the absorption of dietary lipids. Chylomicrons primarily transport dietary triglycerides and some cholesterol from the intestines to peripheral tissues. VLDL particles are assembled in the liver and transport endogenously synthesized triglycerides and cholesterol to peripheral tissues. As VLDL loses triglycerides during circulation, it transforms into intermediate-density lipoproteins (IDL). Finally, LDL carries most of the cholesterol in the bloodstream and is formed when IDL particles undergo further triglyceride removal, leaving a higher proportion of cholesterol and some triglycerides. LDL delivers cholesterol to tissues and can contribute to atherosclerosis when its levels are elevated. HDL plays a role in reverse cholesterol transport. HDL particles are synthesized in the liver and small intestine and collect excess cholesterol from tissues, returning it to the liver for excretion in the form of bile acids. After being synthesized in the intestine, chylomicrons are released into the lymphatic system and eventually enter the bloodstream. They primarily transport dietary triglycerides and cholesterol to peripheral tissues, where they are metabolized by lipoprotein lipase (LPL) on the surface of capillary endothelial cells. LPL hydrolyses triglycerides in chylomicrons, releasing fatty acids for energy use or storage in adipose tissue. As triglycerides are removed, chylomicrons are eventually taken up by the liver for further processing. In the liver, VLDL particles are assembled and released into the bloodstream. Like chylomicrons, VLDL particles are acted upon by LPL in peripheral tissues, releasing fatty acids and transforming into IDL. IDL is taken up by the liver or further processed into LDL. LDL particles carry most of the cholesterol in the blood, and their uptake into cells is mediated by LDL receptors. Excess LDL can accumulate in arterial walls, contributing to the development of atherosclerotic plaques. HDL particles are synthesized in the liver and small intestine and are involved in the reverse cholesterol transport pathway. HDL acquires cholesterol from peripheral tissues, including those in arterial walls, through the action of the enzyme ABCA1. The cholesterol is esterified by lecithin-cholesterol acyltransferase (LCAT), transforming HDL into mature HDL particles. HDL then transports the collected cholesterol back to the liver, where it is excreted as bile acids or reused for various metabolic processes. Lipoprotein metabolism is tightly regulated to maintain lipid homeostasis. Insulin, glucagon, thyroid hormones, and estrogens, play important roles in regulating lipoprotein synthesis, breakdown, and receptor expression. Genetic factors can also influence lipoprotein metabolism, contributing to conditions like familial hypercholesterolemia. We offer a wide product range of research reagents for studying lipoprotein metabolism, including Phospholipase A2 antibodies, COX2 antibodies, NPY2R antibodies, 5 Lipoxygenase ELISA Kits, and Angiotensinogen ELISA Kits. Explore our full lipoprotein metabolism product range below and discover more, for less.