Low-Density Lipoproteins (LDL)

• Low-density Lipoproteins (LDL)

  • Cholesterol is transported to body cells by low-density lipoproteins (LDL) produced by the liver.

  • Most body cells synthesise LDL receptors which then become inserted in their cell membrane.

  • When a molecule of LDL carrying cholesterol becomes attached to a receptor, the cell engulfs the LDL-cholesterol and the cholesterol is released for use by the cell.
• Atherosclerosis

  • Once a body cell contains an adequate supply of cholesterol a negative feedback system is triggered.

  • This inhibits the synthesis of new LDL receptors.

  • This means that less of the LDL-cholesterol is absorbed by the body

  cells.

  • Instead the LDL circulates in the blood where it may deposit cholesterol in the arteries forming atheromas.