intestinal lipid absorption

Definition

Target type: biologicalprocess

A process in which lipids are taken up from the contents of the intestine. [GOC:dos, GOC:sl, PMID:18768481]

Intestinal lipid absorption is a complex process that involves the digestion of dietary fats and their subsequent transport into the bloodstream. It begins in the small intestine, where dietary lipids are emulsified by bile salts secreted from the gallbladder. This emulsification process breaks down large fat globules into smaller droplets, increasing their surface area and making them more accessible to digestive enzymes.

The primary enzyme responsible for lipid digestion is pancreatic lipase, which hydrolyzes triglycerides into monoglycerides and free fatty acids. These products, along with cholesterol and fat-soluble vitamins, are then incorporated into micelles, small spherical structures formed by bile salts.

Micelles transport lipids to the brush border of intestinal epithelial cells (enterocytes). Here, the lipids diffuse across the cell membrane and are re-esterified back into triglycerides, cholesterol esters, and phospholipids. These newly synthesized lipids are packaged into chylomicrons, lipoprotein particles that are released into the lymphatic system.

Chylomicrons travel through the lymphatic system, eventually entering the bloodstream via the thoracic duct. Once in the bloodstream, chylomicrons circulate throughout the body, delivering triglycerides to tissues for energy utilization. Lipoprotein lipase, an enzyme found on the surface of endothelial cells, hydrolyzes triglycerides in chylomicrons, releasing free fatty acids that can be taken up by tissues.

The remaining chylomicron remnants, depleted of triglycerides, are taken up by the liver, where they are further processed. This process involves the removal of cholesterol and other lipids, and the synthesis of new lipoproteins, such as very-low-density lipoproteins (VLDL).

In summary, intestinal lipid absorption is a critical process that involves the breakdown of dietary fats, their transport across the intestinal epithelium, and their packaging into lipoproteins for distribution throughout the body. This complex series of events ensures that essential lipids are absorbed and delivered to tissues where they are required for various metabolic processes.'
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Proteins (3)

Compounds (27)