RESUMO
<p><b>OBJECTIVE</b>To investigate the effect of atorvastatin on platelet aggregation and activation in the acute phase following balloon-induced carotid artery injury in rabbits fed cholesterol-enriched diet.</p><p><b>METHODS</b>Thirty rabbits were randomly divided into 5 equal groups, namely control group, high-cholesterol group, model group, low-dose (5 mg/kg daily) atorvastatin group, and high-dose (10 mg/kg daily) atorvastatin group. Platelet aggregation rate was measured in the rabbits by turbidimetric platelet aggregometry, and the changes of serum P-selectin and thromboxane B2 (TXB2) levels were detected with enzyme-linked immunosorbent assay (ELISA).</p><p><b>RESULTS</b>Compared with those in the control group, serum P-selectin level increased significantly (P<0.01) but platelet aggregation rate and TXB2 level exhibited no obvious changes in high-cholesterol group. After carotid artery balloon injury, P-selectin and TXB2 levels and platelet aggregation significantly increased in cholesterol-fed rabbits, reaching the peak level at 24 h after the injury (P<0.01). Compared with the model group, low-dose atorvastatin treatment significantly decreased P-selectin and TXB2 levels and inhibited platelet aggregation in cholesterol-fed rabbits following carotid artery balloon injury (P<0.01), and such effects of atorvastatin were more prominent at a higher daily dose of 10 mg/kg (P<0.05).</p><p><b>CONCLUSIONS</b>Carotid artery balloon injury in rabbits fed cholesterol-enriched diet can induce platelet activation and aggregation, which reaches the peak level at 24 h after balloon injury and can be dose-dependently inhibited by atorvastatin in the acute phase following the injury.</p>