Abstract:Aim To observe the inhibitory effect of different doses 32 P radiation on the neointimal hyperplasia and stenosis of antologous vein graft. Methods Thirty rabbits underwent 32 P radiotherapy with different doses of 2,4,8,16 μCi/cm 2. HE staining, proliferating cell nuclear antigen immunohistochemical method and computer imaging analysis technique were performed. The neointimal area, the smooth muscle cell (SMC) proliferation index and vessel cavities lost rate were analyzed. Results No neointima was observed in 16 μCi/cm 2 group, but necrosis of most vessel wall cells occurred and the vessels were injured seriously. Thin neointima was formed in 8 μCi/cm 2 group. The neointimal area, SMC proliferation index and cavities lost rate were less than in the control group. There was no significant difference in the parameters between the 2 μCi/cm 2 group, 4 μCi/cm 2 group and control group. Conclusion Low dose 32 P radiation could effectively inhibit the neointimal hyperplasia and restenosis of autologous vein grafts, and the suitable dose was 8 μCi/cm 2 in this model.