Objective To evaluate the effects of 17β-estradiol(E2)-eluting stents on neointimal proliferation of abdominal aortas in high fat diet fed rabbits and to investigate the possible mechanism.Methods Male high fat diet fed rabbits received implantation of 17β-E2-eluting stents,or control phosphorylcholine coated stents or bare metal stents into abdominal aortas as control groups.Histology,immunohistochemistry and Western blot analysis were used to assess the inhibitive effects of E2-eluting stents on neointimal proliferation and and the possible mechanism.Results Western blot analysis revealed marked increase in ERK phosphorylation in 30 min after deployment of phosphorylcholine-coated or bare metal stents,indicating activation of MAP kinase pathway.Immunohistochemistry showed intense staining of phospho-ERK in the medial smooth muscle cells in stent-implanted region.Extensive neointimal hyperplasia developed 12 weeks after stenting.Neointimal area decreased by 36% in E2-eluting stent-implanted animals compared to bare metal stent-implanted animals.In E2-eluting stent-implanted animals,significant inhibition of ERK phosphorylation and neointimal thickening were observed and immunohistochemistry of factor Ⅷ-related antigen demonstrated an accelerated re-endothelialization as compared to the bare metal stent or phosphorylcholine-coated stent-implanted controls.Conclusion E2-eluting stents reduce neointimal proliferation and hence prevent restenosis after angioplasty,possibly by inhibiting ERK activation in smooth muscle cells and promoting re-endothelialization.?更多