低剂量X线辐照对大鼠缺血皮瓣血管新生影响的实验研究

发布时间：2019-02-20 20:31

【摘要】：目的:探讨局部低剂量X线辐照(Low-Dose Irradiation,LDI)对大鼠缺血皮瓣的血管新生的影响及机制。方法:2014年12月至2015年6月选取两月龄Sprague-Dawley大鼠100只,随机分为实验组(A组)、对照组(B),每组各50只。在每只大鼠的背部正中设计1个9 cm×3 cm的缺血随意皮瓣,蒂部靠近尾端,然后将经过消毒处理后的生物隔离膜放置于皮瓣下,然后将皮瓣原位缝合。皮瓣缝合术后A组大鼠背部皮瓣立即给予低剂量X线单次局部照射,总剂量值为0.2 Gy;B组在术后不给予照射。于术后1d、3d、5d、7d以及14d分别对两组皮瓣成活情况行大体观察并计算皮瓣成活率;依次切取标本在正置显微镜、激光共聚焦显微镜下观察其血管生成情况,通过测定新生血管内CD105的含量来计算微血管新生情况。结果:实验组A组在术后3d、5d、7d以及14d,其皮瓣成活率分别为(65.94±3.92)%、(45.01±4.02)%、(31.87±4.19)%,均高于对照组B组的(42.83±4.88)%、(28.08±2.89)%、(15.11±4.94)%。分别对比观察术后1、3、5、7、14天实验组与对照组皮瓣标本荧光染色的切片发现:实验组皮瓣内可见内皮细胞激活明显增多,新生血管形成明显多于对照组,实验组内新生血管的管腔排列较规整,血管层数较多,管腔完整而规则;对照组可见内皮细胞激活较少,并且新生血管的管腔排列稍差,早期血管层数少,并且可见组织水肿较明显。术后第1、3、5、7、14天,实验组皮瓣NMVD值分别为(28.27±2.96)、(21.41±2.41)、(15.24±1.81)、(20.38±2.55)和(30.28±3.66)(条/mm2);均明显高于对照组皮瓣NMVD的(14.94±2.01)、(9.13±1.03)(6.92±1.07)(10.07±1.81)和(18.21±2.11)(条/mm2)。结论:低剂量X线辐照可以提高缺血皮瓣的成活率。可能机制为低剂量的X线照射能够促进内皮细胞的激活,增加VEGF的表达,通过促进皮瓣内的血管新生,增加缺血皮瓣成活率。
[Abstract]:Objective: to investigate the effect and mechanism of local low dose X-ray irradiation (Low-Dose Irradiation,LDI) on angiogenesis of ischemic skin flap in rats. Methods: from December 2014 to June 2015, 100 two-month-old Sprague-Dawley rats were randomly divided into experimental group (A group) and control group (50 rats in each group). A 9 cm 脳 3 cm ischemic random flap was designed in the middle of the back of each rat. The pedicle was located near the end of the flap. Then the disinfected biofilm was placed under the flap and the flap was sutured in situ. Group A received single local irradiation of low dose X-ray immediately, and the total dose of 0. 2 Gy;B group was not irradiated after operation. The survival rate of the two groups was observed and the survival rate of the flap was calculated at 1 day, 3 days, 5 days, 7 days and 14 days, respectively. The angiogenesis of the specimens was observed under a positive microscope and a confocal laser microscope, and the microvascular neovascularization was calculated by measuring the content of CD105 in the neovascularization. Results: the survival rate of flap in group A was (65.94 卤3.92)%, (45.01 卤4.02)%, (31.87 卤4.19)% respectively, which was higher than that in group B (42.83 卤4.88)%. (28.08 卤2.89)%, (15.11 卤4.94)%. The fluorescence staining of the flaps in the experimental group and the control group was observed on the 1st day, 3rd day and 714 days after operation. The results showed that the activation of endothelial cells and the formation of neovascularization in the experimental group were significantly increased than those in the control group. In the experimental group, the neovascularization lumen was arranged regularly, the number of vascular layers was more, and the lumen was intact and regular. In the control group, the endothelial cells were less activated, the lumen arrangement of neovascularization was slightly worse, the number of early vascular layers was less, and the tissue edema was obvious. The NMVD values of the flaps in the experimental group were (28.27 卤2.96), (21.41 卤2.41), (15.24 卤1.81), (20.38 卤2.55) and (30.28 卤3.66) (strip / mm2), respectively. All of them were significantly higher than those of the control group (14.94 卤2.01), (9.13 卤1.03) (6.92 卤1.07) (10.07 卤1.81) and (18.21 卤2.11) (strip / mm2). Conclusion: low dose X-ray irradiation can improve the survival rate of ischemic flap. The mechanism may be that low dose X-ray irradiation can promote the activation of endothelial cells, increase the expression of VEGF, and increase the survival rate of ischemic flap by promoting angiogenesis in the flap.
【学位授予单位】：苏州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：R622

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