Statins: Cardiovascular Risk Reduction in Percutaneous Coronary Intervention—Basic and Clinical Evidence of Hyperacute Use of Statins

Figure 1

Regulation of LDL-R in 5 steps. Step 1. The LDL is recognized in apo-B100 by the LDL-R located in the membrane structures “clathrin-coated pits.” Step 2. It forms an endocytic vesicle or endosome containing LDL and LDL-R, the LDL-R is dissociated through lowering of the pH within the endosome, and the LDL is transferred to the lysosomes. Step 3. In lysosomes, apo-B100 is hydrolyzed into amino acids and cholesteryl ester is deesterified by enzymatic hydrolysis. Step 4. Nonesterified cholesterol (hydrophobic) is transported to the cell membranes by the “hydrophobic handoff mechanism”; in this mechanism Niemann Pick 2 and 1 proteins form a hydrophobic core containing nonesterified cholesterol. Step 5. Nonesterified cholesterol is transferred by the binomial NP2-NP1 to cell membranes, its concentration in the Sarcoplasmic Reticulum/Golgi Apparatus membranes is the signal that inhibits the dissociation of SCAP-SREBP and thus blocks the synthesis of LDL-R.