Abstract:Aim To investigate the effect of 17β-estradiol(17β-E2) eluting stent implantation on neointima proliferation and re-endothelialization of abdominal aorta in rabbits. Methods Male rabbits were divided into 3 groups after hyperlipemia feed.17β-E2 eluting stents,phosphorylcholine(PC) coated metal stents and bare metal stents were implanted in each groups.The stented aortas tissue of 6 rabbits were removed at 2 weeks,4 weeks and 12 weeks from each group respectively.Lumen area,thickness and area of neointima at different time after stent implantation were measured by computer image analysis technique.Immunohistochemistry was used to detect the positive rate of factor Ⅷ expression of the arterial intima at different time in order to assess re-endothelialization degree. Results The mean injury scores were similar in three groups(2.17±0.22,(2.18)±0.21 and 2.17±0.19,p>0.05).The neointima areas had increased at 2 weeks after stent implantation,and the lumen loss rates were less than 50% at 12 weeks in three groups.At 12 weeks neointima area reduced 36% in 17β-E2 eluting stent group compared with that of bare metal stent group,and had no difference between PC coated and bare metal stent groups.The ratio of neointima area at the time of 2 week and 12 week was compared within each group,and the results showed that the 17β-E2 group had significantly higher ratio than other two groups(0.77,0.61 and 0.61,respectively,p<0.01).At the time of 2 week the re-endothelialization rate in 17β-E2 eluting stent group was obviously higher than PC coated stent and bare metal stent groups((78.4%)±2.3% vs 61.4%±3.4% and 62.8%±2.9%,p<0.01),and nearly complete re-endothelialization were found at 4 weeks after stent implantation procedure in three groups. Conclusions 17β-E2 eluting stent has ideal effect in preventing restenosis by inhibition of neointima proliferation as well as acceleration of re-endothelialization of treated arteries.