Summary
Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase are widely used in the
management and prevention of cardiovascular disease. In addition to its major activity,
plasma lipid lowering, statins have shown a wide spectrum of additional effects that
may contribute to their benefits in the prevention of cardiovascular disease. Our
objective was to study whether treatment with a statin, pravastatin, could reduce
thrombosis triggered by damaged vessels without changing plasma cholesterol levels.
A cholesterol-clamp animal model was developed by feeding swine for 100 days on an
hypercholesterolemic (HL) diet; in the last 50 days, they were randomly assigned to
receive either placebo (HLC) or pravastatin (5mg . kg−1. day−1) (HLP) in addition to the hypercholesterolemic diet. A normocholesterolemic control
group (NLC) was simultaneously studied. There were no significant differences in total
cholesterol, LDL and HDL plasma levels between the two groups; however, mural thrombosis
triggered by both an eroded and disrupted vessel wall was significantly inhibited
by pravastatin (P<0.05). Axial dependence analysis of platelet deposition revealed that pravastatin
treatment reduced the increase in platelet deposition associated to the shear rate
increase at the stenosis. Additionally, pravastatin treatment significantly reduced
platelet membrane RhoA expression (P <0.05) and vascular wall tissue factor (TF) protein expression (P <0.05). In addition to its lipid lowering effects, pravastatin can reduce blood thrombogenicity
by mechanisms independent of plasma cholesterol lowering.
Keywords
Hypercholesterolemia - statins - thrombosis - pravastatin - platelets