^(103)Pd支架预防支架内再狭窄的量效及机制

The dose-effect and its mechanisms of preventive effects of ^(103) Pd radioactive stent on in-stent restenosis in rabbits

目的 探讨1 0 3Pd支架对血管成形术后再狭窄的预防作用的量效关系及其机制。方法 5 0只雄性新西兰白兔随机分为普通支架组和各剂量的核素支架组 (8只 组 )。支架置入术后 8周行腹主动脉血管内超声和造影检查、行免疫组化染色并检测细胞凋亡。结果 在核素支架组 ,随剂量增加 ,支架段最小内径和支架内管腔面积均增大而狭窄程度减小。核素支架各组增殖细胞核抗原(PCNA)阳性细胞率均显著小于普通支架组 ,而凋亡指数除 5Gy组外均显著大于普通支架组。结论 1 0 3 Pd支架可抑制支架内血管内膜的增生 ,减少支架内狭窄的程度 ,显示出量效关系。1 0 3Pd支架既抑制血管平滑肌细胞 (VSMC)增生也诱导细胞凋亡。

Objective To investigate the dose-response and its mechanisms of preventive effect of 103 Pd radioactive stent on restenosis in rabbits after balloon injury. Methods The abdominal arteries of the rabbits randomized into common or radioactive stent groups (including 5 Gy, 15 Gy, 25 Gy, 35 Gy groups) were balloon injured, and then stented. Intravascular ultrasound and angiography on abdominal arteries, immunohistochemical study of PCNA, and TUNEL assay were performed 8 weeks after stenting. Results Both the minimal lumen diameters and in-stent lumen areas in 103 Pd radioactive stent groups [(1.94±0.21) mm and (5.99±0.43) mm2, (2.17±0.12) mm and (7.01±0.93) mm2, (2.43±0.22) mm and (8.09±0.89) mm2, (2.56±0.27) mm and (8.49±0.54) mm2 in turn in 5 Gy, 15 Gy, 25 Gy, 35 Gy groups, respectively]were significantly improved with increases of the doses at the end of 8 weeks,revealing a dose-response effect. The positive ratio of PCNA in each 103 Pd stent group was reduced as compared with that in commen stent group (P<0. 01), while the ratio of TUNEL positive cells in 15, 25 and 35 Gy of radioactive stent groups was significantly higher than that in commen stent group (P<0.001). Conclusion 103Pd radioactive stent could dose dependently restrain in-stent neointimal hyperplasia, and reduce the magnitude of in-stent stenosis, and the optimal prescribed dose was about 25 Gy. The possible mechanisms could be both the inhibition of proliferation and the induction of the apoptotic cell.