【摘要】 目的观察纯β射线32P血管内照射对经皮血管腔内血管成形术(PTA)后平滑肌细胞增生及内膜增殖的影响,研究β射线血管内照射对血管成形术后再狭窄的抑制效应。材料和方法雌性大白兔18只,随机分成对照组和照射组,采用Clowes球囊扩张法制作右侧髂动脉再狭窄模型,对照组球囊内充盈生理盐水,照射组球囊内充盈液体放射源32P,根据观察时间点的不同将对照组和照射组均随机分成3天组、10天组和4周组,每组3只。在不同的观察时间点对标本进行组织病理、免疫组织化学和电镜分析。结果光镜下PTA后3天对照组内弹力板处可见少量增殖的平滑肌细胞,照射组内弹力板处未见增殖的平滑肌细胞;10天对照组血管内膜可见大量增殖的平滑肌细胞,照射组血管内膜仅见少量增殖的平滑肌细胞;4周对照组动脉壁明显增厚,血管腔明显狭窄,照射组动脉壁厚度正常,血管腔未见狭窄(P<0.01)。增殖细胞核抗原(PCNA)免疫组化染色PTA后3天和10天PCNA标记指数(PCNALI)对照组明显高于照射组(P<0.01);对照组的阳性细胞数尤以PTA后10天为高(P<0.01);4周,对照组和照射组阳性细胞数均明显减少;电镜下PTA后3天对照组平滑肌细胞呈增生状态,照射组平滑肌细胞呈静止状态;10天对照组平滑肌细胞呈合成表型,照射组平滑肌细胞变性坏死,合成减少;4周对照组动脉壁内膜仍有合成表型的平滑肌细胞,照射组平滑肌细胞呈收缩表型。结论血管内照射能显著降低平滑肌细胞的增殖,从而起到抑制再狭窄作用,平滑肌细胞的增殖和胶原的合成受到抑制在血管内照射抑制血管成形术后再狭窄的过程中起重要作用。更多还原

【Abstract】 Objective: To observe the effect of β-particle of 32P brachytherapy on smooth muscle cell(SMC) proliferation and intimal hyperplasia, and to study the inhibition of restenosis after percutaneous transluminal angioplasty(PTA) by β-particle endovascular radiation therapy. Materials and Methods: Eighteen white female rabbits were divided randomly into control group and test group. Each group were divided into the 3rd day, the 10th day and the 4th week group according to the sacrificed time. Each group had 3 rabbits. The animal model of right iliac artery stenosis was made by the method of Clowes balloon dilation. The balloon was filled with 32P liquid that act as the radiation source in the test groups. While in the control groups the balloon was filled with saline. Pathology, immunohistochemistry and electron microscope analysis were performed on the lesion sample at different observing time point. Results: Pathology analysis: On the 3rd day after PTA, a few proliferating SMCs can be seen in the internal elastic lamina of the control group. While in the irradiation group, no proliferating SMCs can be found. On the 10th day, lots of proliferating SMCs can be seen in the vascular intima in the control group. In the irradiation group, only a few proliferating SMCs can be seen. On the 4th week, the vessel wall thickened and vascular lumen narrowed predominantly in the control group. In the irradiation group, the thickness of the vessel wall was normal. Lumen stenosis did not occur(P<0.01). Proliferating cell nuclear antigen(PCNA) immunohistochemistry stain analysis: In control group the PCNA label index on the 3rd and 10th day was higher than that in the irradiation group(P<0.01). The number of positive stain cells of the control group is more obvious on the 10th day group than other groups(P<0.01). On the 4th week, the number of positive stain cells in both the control group and the irradiation group decreased significantly. Electron microscope analysis: on the 3rd day after PTA, the SMCs in the control group displayed a synthetic phenotype. While in the irradiation group, degeneration and necrosis occurred among SMCs. On the 4th week, although SMCs of synthetic phenotype in the control group still can be seen, but their number began to decrease. SMCs in the test group displayed a contractile phenotype. Conclusion: Endovascular radiation therapy can inhibit the proliferation of SMCs predominantly, thus can prevent the occurrence of restenosis. The inhibition of the SMCs proliferation and collagen synthesis were supposed to be one of the mechanisms that endovascular radiation therapy inhibit restenosis after PTA.更多还原