Local Application of Rapamycin Inhibiting Restenosis in Experimental Vein Graft

Aim To examine the effect of rapamycin on reducing neointima formation and the proliferition of vascular smooth muscle cell(VSMC) after local application of rapamycin in a mouse model of vein graft. Methods Vein graft model was established in 30 Wistar mice which were randomly divided into two groups: rapamycin group and control group.In the rapamycin group,200 μg of rapamycin was applied locally.The control group did not receive local treatment.Graft veins were harvested 4 weeks later and underwent morphometric analysis as well as immunohistochemical analysis. Results Morphometric analysis indicate that the thickness of neointima in rapamycin group is obviously less than that in control group(13.8±0.6 μm vs 36.4±1.6 μm,P0.05).Immunohistochemical analysis shows that the reduction of bcl-2 positive cells in vascular smooth muscle of rapamycin group was 16.6%±2.2% vs 51.3%±3.4%(P0.05) and the decreased amount of bax positive cell was 63.3%±3.2% vs 16.3%±1.3%(P0.05). Conclusion Local application of rapamycin can inhibits restenosis in experimental vein graft.