Cholesterol present in LDL

On accumulation in the cell inhibits replenishment of LDL receptors If LDL cholesterol is increased inside the cell, it down regulates LDL receptors so that further uptake is inhibited. HDL cholesterol is the cholesterol that is removed from peripheral tissues; LDL cholesterol represents the cholesterol which is to be delivered to peripheral tissues. LDL binds to LDL receptors and whole LDL particle is endocytosed by receptor mediated endocytosis via clathrin-coated pits (not by diffusion:- diffusion and endocytosis are different processes). Intracellular cholesterol activates intracellular enzyme acyl-CoA cholesterol acyl transferase (ACAT).