去内皮、冻干辐照后异体小血管的组织结构、物理性能及抗原性变化

The structural,physical performance and antigenic changes of allogenic small vessels after treatment by removal of endothelial cells,gelsiccation and irradiation

目的研究去内皮、冻干辐照后同种异体小血管的组织结构、物理性能及抗原性的变化,旨在了解处理后的异体血管是否适用于血管移植。方法将血管随机分为A,B两组;A组为对照组,B组为去内皮冻干辐照处理组。光镜下观察每组血管的组织结构,电镜下观察血管去内皮化情况,测出血管张力在达到15,30,45,60,90,120N及180N时的扩张直径、伸展长度及血管在横向和纵向被拉断时所能承受的最大拉力,并计算出血管在该张力下的横向和纵向变化率;采用免疫组化SP法检测处理前后主要组织相容性复合体(MHC)-Ⅱ类抗原的表达水平。结果处理组血管组织结构保持良好,两组血管在不同张力下的横向及纵向变化率差异无统计学意义(P>0.05)。处理组血管在横向上被拉断时所能承受的最大张力和在纵向上被拉断时所能承受的最大张力显著大于对照组(P<0.01及P<0.05)。处理组MHC-Ⅱ类抗原水平明显低于对照组(P<0.01)。结论经去内皮、冻干辐照处理后异体小血管组织结构未发生改变,且在正常生理范围内保留一定的血管物理性能;MHC-Ⅱ类抗原水平下降明显。提示,经处理的血管基本符合血管移植的要求,是小口径同种异体血管移植的理想材料。

Objective To investigate the structural, physical performance and antigenic changes of allogenic small vessels after treatment by removal of endothelial cells, gelsiccation and irradiation. This research was intended to learn whether treated allogenic small vessels are suitable for blood vessel transplantation. Methods The blood vessels were randomly divided into A group and B group, in which A group was control group while B group had removal of endothelial cells as well as gelsiccation and irradiation. The tissue structure of each group was examined by light microscopy, and the condition after removal of endothelial cells was examined under electron microscope. The dilated diameter, expanded length and the largest force that the vessels could sustain in transverse and perpendicular directions when the vascular tension reached 15, 30,45, 60, 90, 120N and 180N were calculated, and the degree of change both in transverse and perpendicular directions of the vessels under such forces was calcalated. Finally, the expressive level of major histocompatibility complex （ MHC ） - Ⅱ antigens both pre-and post treatment was detected using immunohistochemistry S-P statistic way. Results The blood vessels maintained almost the same tissue structure after treatment in B group, and the changed rates both in transverse and perpendicular directions of the vessels under different tensions of the two groups had no statistical significance （ P 〉 0.05 ）. However, in B group, the greatest tension that the vessels could withstand in the transverse and perpendiculaar direction at the time of rupture was significantly greater than that of the control （ P 〈 0. 01 and P 〈 0. 05, respectively ）. The MHC- Ⅱ antigen level of B group was significantly lower compared to control group （ P 〈 0.01 ）. Conclusions There is no obvious change in tissue structure of allogenic blood vessels after treatment by removal of endothelial cells, gelsiccation and irradiation, meanwhile, the blood vessels could maintain certain physical characteristics. The MHC-Ⅱ antigen level decreased dramatically. The vessel after treated with the method of B group basically meets the demands for vascular transplantation, and is an ideal material for such kind of operation.