OBJECTIVETo explore the effects of simvastatin on vascular endothelial cell apoptosis and Bcl-2 protein expression in the aorta in a rat model of atherosclerosis.

METHODSThirty-six rats were randomized into control group (n=10), atherosclerosis model group (n=13) and simvastatin intervention group (n=13). In the latter two groups, rat models of atherosclerosis were established by intraperitoneal injection of vitamin D3 combined with high-fat feeding for 6 weeks, and the control rats were fed with regular diet. In the intervention group, the rats were further fed with high-fat diet with daily simvastatin treatment for 4 weeks. After the treatments, the pathological changes and plaque in the thoracic aorta were observed, and the expression of Bcl-2 protein was detected with immunohistochemistry. TUNEL assay was used to determine the apoptosis index (AI) of the vascular endothelial cells.

RESULTSCompared with that in the control group, Bcl-2 protein expression in the aorta of atherosclerotic rats was significantly decreased (P<0.05); simvastatin treatment obviously increased the expression of Bcl-2 protein in atherosclerotic rats (P<0.05) to a level similar to that in the control group. The AI was the highest in the model group (P<0.05) and comparable between the control and simvastatin treatment group.

CONCLUSIONThe therapeutic effect of simvastatin against atherosclerosis is probably mediated by up-regulation of Bcl-2 protein, which inhibits vascular endothelial cell apoptosis in rats with aortic atherosclerosis.