Summary
Apart from reducing systemic lipid levels, statins may improve the clinical course
of atherosclerosis by exerting favourable pleiotropic effects on the vessel wall.We
studied the effects of rosuvastatin, a new, potent 3-hydroxy-3-methylglutaryl coenzyme
A (HMG-CoA) reductase inhibitor, on vascular remodelling after endothelial injury
in the hyperlipidaemic apolipoprotein E-knockout (apoE-/-) mouse. ApoE-/- mice, 22-weeks-old,
were injected daily with rosuvastatin at a low (1 mg/kg; n=27) or high dosage (10
mg/kg; n=24), or with vehicle alone (n=26).After treatment for 2 weeks,endothelial
injury and thrombosis of the carotid artery was induced with 10% ferric chloride.Treatment
was then resumed for a 3-week period.Although statin treatment did not affect the
plasma lipid levels of mice, mean times to arterial thrombosis were prolonged in the
low-dose and the high-dose group compared to controls (P<0.05 and P<0.01 respectively). Interestingly, rosuvastatin withdrawal 4 days before injury completely
reversed the antithrombotic effects of the drug. In follow-up studies 3 weeks after
injury,deposition of fibrin in the vessel wall was significantly reduced in the rosuvastatin-treated
animals. There was an increase in the content of α -actin-positive smooth muscle cells
(P =0.008) and collagen fibers (P<0.001), and a concomitant decrease in the number of oxLDL-containing macrophages
(P<0.001). Overall, the neointimal area and the severity of luminal stenosis were significantly
reduced in statin-treated mice. Thus, rosuvastatin attenuates arterial thrombosis
and neointima formation, and it may stabilise vascular lesions developing after endothelial
injury in mice.These effects are independent of systemic lipid lowering.
Keywords
Animal models - atherosclerosis - tissue remodelling - fibrinogen / fibrin - restenosis