兔颈动脉移植后血管内皮型一氧化氮合酶基因表达的变化及意义

The Variation and Its Significance of Expression of Endothelial Nitric Oxide Synthase after Rabbits' Carotid Allografts

目的探讨兔颈动脉移植后移植血管段内皮型一氧化氮合酶信使核糖核酸(eNOSmRNA)表达的变化及其意义。方法建立大白兔颈动脉移植模型。将30只兔按随机数字表法分为4组。A组(n=3)自体血管移植;B组(n=9)新鲜异体血管移植;C组(n=9)同种异体血管经青霉素和链霉素处理常温保存后移植;D组(n=9)同种异体血管经青霉素和链霉素处理冷冻保存后移植。观察比较移植后1～3周移植血管段组织形态学变化和eNOS mRNA的表达。结果光学显微镜下观察A组结构正常,仅有炎性细胞浸润;其余各组术后1周内膜开始增生,2周内膜明显增厚,3周内膜、中膜增厚最明显,同时伴有血栓形成。其中B组改变最严重,B组血管移植后eNOS mRNA表达明显低于其他三组(P<0.05)。结论同种异体动脉血管移植后,血管eNOS基因表达明显下调,可造成移植后血管内膜增生和血栓形成。

Objective To assess the variation and its significance of messenger ribonucleic acid(mRNA) expression of endothelial nitric oxide synthase (eNOS) in allografts of common carotid transplantation model in white rabbits. Methods To establish an animal model of common carotid transplantation in vivo, 30 rabbits were divided into four groups with random number table. Group A (n=3): autografts; group B (n=9): allografts with the least treated; group C (n=9): allografts treated by penicillin/streptomycin and preserved under room temperature; group D (n=9): allografts treated by penicillin/streptomycin and cryopreserved in liquid nitrogen. All the transplanted grafts were harvested 1-3 weeks later, then compared and evaluated the histomorphological variation and eNOS mRNA expression. Results The vascular structures of autografts in group A were kept approximately normal, only a few infiltration of inflammatory cells could be found. The structural variations of allografts in other trial groups behaved similarly as, intima proliferation in the 1st week, intima hyperplasia in the 2nd week, and both intima and media hypertrophy in the 3rd week. And also there seemed that luminal thrombosis could be found in all the allografts. Allografts in group B were destructed utmost the worst in all the groups. The expression of eNOS mRNA in allografts of group B was significantly less than that in other groups (P<0.05). Conclusion The down-regulation of eNOS mRNA expression might lead to intima hyperplasia and thrombosis of allografts.