Effects of lovastatin therapy on LDL receptor activity in circulating monocytes and on structure and composition of plasma lipoproteins

Abstract The effect of lovastatin therapy on LDL-receptor activity in fresh monocytes and on the structure and composition of lipoproteins was determined in 9 patients with familial hypercholesterolemia (FH) and 8 patients with non-familial hypercholesterolemia (NFH). Lovastatin reduced LDL-cholesterol levels by 34.8 and 47.5%, respectively, in the 2 groups of patients, and plasma apo B levels by 33.3 and 42.5%. LDL receptor activity in fresh monocytes increased by 53% and 86% respectively. HDL-cholesterol and plasma apo A-I levels increased only in the NFH group, by 10.2 and 7.1%. Lipoproteins were separated by centrifugation on a zonal rotor. Except for the intermediate density lipoprotein (IDL) fraction, no changes were observed in the structure and composition of the various lipoproteins. The investigations thus demonstrated that lovastatin therapy is associated with a measurable and significant increase of LDL-receptor activity in circulating monocytes that may contribute to the lipid lowering action of the drug.