老年大鼠后肢高血流剪切力诱导的侧支血管生长及其与血管生成素-1表达的关系

目的:检测老年大鼠后肢高血流剪切力诱导的侧支血管生长情况及其与血管生成素-1(Ang-1)表达的关系。方法:实验组取12只老年健康SD大鼠,左侧行股动静脉单纯分离,右侧行股动静脉吻合术,在1周与4周时间点分别处死6只大鼠,采用血管造影与共聚焦免疫荧光术分别观察侧支血管生长情况及Ang-1在血管处的表达情况,正常组3只大鼠用作正常对照组。结果:正常对照组的侧支血管生长与假手术侧无明显差异,但吻合侧的侧支血管生长明显增加,且4周组吻合侧的血管生长多于1周组。正常对照组的血管Ang-1表达与假手术组无明显差异,仅在血管外膜及部分中膜存在表达;1周组吻合侧的Ang-1不仅在原有表达区域明显表达增加,且在内皮细胞处也有所表达;4周组吻合侧Ang-1在血管各层均明显存在高表达。与假手术侧相比,吻合侧Ang-1表达增加,差异具有统计学意义;4周吻合侧的Ang-1荧光强度较1周吻合侧明显增加,其差异也具有统计学意义。结论:老年大鼠后肢高血流剪切力模型可以诱导侧支血管的生长,且与相应部位血管Ang-1表达的增长呈正相关。

Collateral growth induced by high fluid shear stress in the hindlimbs of aged rats and its relationship with the expression of angiopoietin-1

Objective:To detect the collateral growth induced by high fluid shear stress in the hindlimbs of aged rats and its relationship with the expression of angiopoietin-1 (Ang-1).Methods:Twelve healthy aged rats were chosen as the study group,where the left femoral arteries and veins of rats were separated and the right femoral arteries and veins were anastomosed.One week and four weeks later,six of them were sacrificed each time respectively.The collateral growth was detected by angiography and the expression of Ang-1 was detected by confocal immunofluorescence.Three other aged rats were used as normal controls.Results:The collateral growth of the control group and sham-operation group showed no significant difference.The collateral growth of anastomosis group was significantly increased,which included the significant difference between one-week group and four-week group.The Ang-1 expression of the control group and sham-operation group showed no significant difference,which was very weak and only appeared in tunica media and parts of adventitia.Oneweek anastomosis group showed more Ang-1 expression not only in the same area but also in the endotheliurn.And four-week anastomosis group showed highly positive expression of Ang-1.In the anastomosis group,the expression of Ang-1 was significantly increased.Besides,four-week anastomosis group also showed significant increase compared to one-week anastomosis group.Conclusion:Collateral growth can be induced by high fluid shear stress in the hindlimbs of aged rats,which is positively related to the increased expression of Ang-1 in the related area.