Cholesterol travels through the bloodstream in particles containing cholesterol, cholesterol ethers, phospholipids, and proteins. Low-density lipoprotein particles transport cholesterol from the liver to other tissues. High-density lipoproteins are cholesterol scavengers, removing cholesterol from the surfaces of membranes and delivering it back to the liver, where it is converted into bile acids. The more cholesterol we eat, the less the body synthesizes. Cholesterol also inhibits the synthesis of the low-density lipoproteins, which means the less the body can get rid of by bringing it into target cells.
Cholesterol is also the precursor of the bile acids.
The bile acids are synthesized in the liver and stored in the gallbladder. They are then secreted into the small intestine where they are emulsifying agents. This enables fats and oils to be digested by water-soluble digestive enzymes. Cholesterol is also the precursor of vitamin D. Clinical Treatment of High Cholesterol Compactin and Lovastatin are used clinically to decrease the concentration of cholesterol levels. They inhibit the enzyme that catalyzes the reduction of hydroxymethylglutaryl-CoA to mevalonic acid.