Simvastatin exerts both anti-inflammatory and cardioprotective effects in apolipoprotein E-deficient mice

Abstract

Background - Simvastatin attenuates ischemia and reperfusion in normocholesterolemic animals by stabilizing endothelial nitric oxide synthase activity and inhibiting neutrophil-mediated injury. Because endothelial dysfunction is a detrimental effect of hypercholesterolemia, we examined whether short-term treatment with simvastatin could inhibit leukocyte-endothelium interaction and attenuate myocardial ischemia-reperfusion injury in apoE-deficient (apoE-/-) mice fed a high-cholesterol diet. Methods and Results - We studied leukocyte-endothelium interactions in apoE-/- mice fed a normal or a high-cholesterol diet after short-term (ie, 18 hours) simvastatin treatment. We also studied simvastatin treatment in myocardial ischemia-reperfusion injury by subjecting apoE-/- mice to 30 minutes of ischemia and 24 hours of reperfusion. ApoE-/- mice fed a high-cholesterol diet exhibited higher blood cholesterol levels, which were not affected by short-term simvastatin treatment. However, the increased leukocyte rolling and adherence that occurred in cholesterol-fed apoE-/- mice (P<0.001 versus control diet) were significantly attenuated by simvastatin treatment (P<0.01 versus vehicle). Cholesterol-fed apoE-/- mice subjected to myocardial ischemia-reperfusion also experienced increased myocardial necrosis (P<0.01 versus control diet), which was significantly attenuated by simvastatin (P<0.01 versus vehicle). Simvastatin therapy also significantly increased vascular nitric oxide production in apoE-/- mice. Conclusions - Simvastatin attenuates leukocyte-endothelial cell interactions and ameliorates ischemic injury in hypercholesterolemic mice independently of lipid-lowering actions.