The Effects of Simvastatin on the Expression of Lipoprotein Associated Phospholipase A2 in the Atherosclerotic Rabbits

• 1、Department of cardiology, Peking university people’s hospital

Abstract：[objective] To investigate the effects of simvastatin on the expression and activity of Lp-PLA2 in the atherosclerotic rabbits. [Methods] 24 four months male New Zealand White (NZW) rabbits were randomly assigned to three groups: control group (n=8), fed a normal diet for 12 weeks; atherosclerosis (AS) group, fed a high-cholesterol diet for 12 weeks; simvastatin group, fed a high-cholesterol diet for 8 weeks and the diet containing simvastatin (5mg/kg) for additional 4 weeks. Blood samples were taken at times of 0, 4, 8, 12 weeks and the aortic samples were obtained at the end of the study, which was to determined plasma and aortic Lp-PLA2 activity and Lp-PLA2 expression in atherosclerotic plaque and composition of aortic plaques. [Results] (1) Lp-PLA2 activity of plasma and atherosclerotic aortas increased significantly of AS groups rabbits compared with control group. Positive in immunocytochemistry for Lp-PLA2 were detected in AS rabbits. However, simvastatin reduced Lp-PLA2 activity in rabbit plasma and aortas. Moreover, simvastatin treatment inhibited the protein expression of Lp-PLA2 in lesions. (2) Simvastatin treatment significantly reduced intima-media ratio. (3) Compared with AS group, simvastatin decreased the macrophage content and extracellular lipid deposition in the cross-sectional area of lesion. On the other hand , the smooth muscle cells were significantly increased by treatment. [Conclusions] The expression and enzyme activity of Lp-PLA2 are increased in atherosclerosis lesion. Simvastatin treatment significantly reduced Lp-PLA2 activity in rabbit plasma and aortas as well as the protein expression in AS lesion. Furthermore, simvastatin exerts the anti-inflammatoy roles and stabilized atheromatous plaques.

Keywords： Lipoprotein associated phospholipase A2 Simvastatin Atheroclerosis Inflammation