Are chylomicrons exogenous?
Are chylomicrons exogenous?
Exogenous pathway for lipid metabolism: Dietary cholesterol and fatty acids are absorbed. Triglycerides and cholesterol combine to form chylomicrons. Chylomicrons enter the circulation and travel to peripheral sites.
What is the exogenous pathway?
The exogenous pathway is utilized by specialized antigen-presenting cells to present peptides derived from proteins that the cell has endocytosed. The peptides are presented on MHC class II molecules. This fuses with a late endosome containing the endocytosed, degraded proteins.
What are exogenous lipids?
Abstract. Lipids are body fats that are either synthesized within cells (endogenous lipids) or derived from dietary fat (exogenous lipids).
In what form is exogenous triglycerides transported in the body?
The chylomicrons are considered transport vehicles for exogenous triglycerides. In other words, dietary fat is absorbed through the intestine in the form of chylomicrons. After a meal, the liver will clear the chylomicrons from the blood and use the triglyceride component to form the prebeta-lipoproteins.
What is the difference between endogenous and exogenous pathway?
The key difference between endogenous and exogenous antigens is that the endogenous antigens generate within the cells while the exogenous antigens come from the outside of the body. Hence, endogenous antigens are intracellular while exogenous antigens are extracellular.
What is the difference between endogenous and exogenous cholesterol?
1). In the endogenous path- way, cholesterol is synthesized by the liver and extra- hepatic tissues and secreted into plasma, whereas the intestine is the primary site of the exogenous pathway of dietary cholesterol uptake[1–3]. Alteration of either path- way will affect the concentration of plasma cholesterol.
What is the function of chylomicrons?
Chylomicrons. Chylomicrons (Fig. 20-14) are formed in the intestinal epithelium to transport long-chain triglycerides to the tissues. Medium- and short-chain fats are transported directly to the liver through the portal circulation without packaging into lipoprotein particles.
What is exogenous and endogenous pathway?
In the endogenous path- way, cholesterol is synthesized by the liver and extra- hepatic tissues and secreted into plasma, whereas the intestine is the primary site of the exogenous pathway of dietary cholesterol uptake[1–3]. Alteration of either path- way will affect the concentration of plasma cholesterol.
Which is an exogenous pathway in chylomicron metabolism?
Chylomicron metabolism the exogenous pathway. LPL acts on lipoprotein particles passing through the capillaries, hydrolysing triacylglycerol molecules to release non-esterified fatty acids which may be taken up into the tissue for esterification (and hence storage – mainly in adipose tissue) or oxidation (in muscle).
What is the role of the exogenous pathway?
Ezetimibe, the first of these new compounds, inhibits intestinal absorption of dietary and biliary cholesterol, and lowers total cholesterol and low-density lipoprotein cholesterol (LDL-C) levels in humans.
How are Lipids transported through the exogenous lipoprotein pathway?
The exogenous lipoprotein pathway starts with the incorporation of dietary lipids into chylomicrons in the intestine. In the circulation the triglycerides carried in chylomicrons are metabolized in muscle and adipose tissue by lipoprotein lipase and chylomicron remnants are formed.
How are triglycerides carried in chylomicrons metabolized?
In the circulation, the triglycerides carried in chylomicrons are metabolized in muscle and adipose tissue by lipoprotein lipase releasing free fatty acids, which are subsequently metabolized by muscle and adipose tissue, and chylomicron remnants are formed. Chylomicron remnants are then taken up by the liver.