大段同种异体皮质骨移植后VEGF表达的实验研究

Vascular endothelial growth factor expression inthe healing process of massive allogenic cortical transplants

目的观察大段同种异体皮质骨移植后的血管内皮生长因子(VEGF)表达情况,探讨VEGF在异体皮质骨“爬行替代”过程中表达的意义。方法新西兰大白兔60只,30只用于制备深冻异体骨。30只手术移植异体骨,术后第2、4、6、8、12周双侧尺桡骨干X线摄片,记录移植骨周围和近、远侧结合部骨痂生长情况。1、2、4、6、8、12周取材,观察异体骨移植后VEGF免疫组化染色结果。结果1移植后早期(1～2周),X线观察无骨痂形成,VEGF阳性表达只出现在移植骨周围软组织内;2移植后中期(4～6周),X线观察出现外骨痂和环状骨痂。移植骨外骨痂和结合部骨痂的VEGF阳性表达到最高峰,移植骨内部VEGF开始表达;3移植后晚期(8～12周),X线观察结合部的间隙完全消失,形成新的髓腔。成熟的外骨痂和结合部骨痂VEGF阳性表达减少,移植骨内部VEGF阳性表达的细胞大量出现。结论VEGF参与了大段同种异体皮质骨的“爬行替代”过程,与异体皮质骨的血运重建密切相关。异体骨不同部位“再血管化”的时机是不同的。

Objective To observe the expression of VEGF in the creeping substitution process of massive allogenic cortical transplants and explore the significance.Methods Thirty New Zealand rabbits were the suppliers of allogenic cortex,Both radius of the other 30 rabbits were implanted frozen bone transplants.Underwent X-ray,the healing results of external surface and osteosynthesis sites were observed postoperatively at 2,4,6,8 and 12 weeks.Specimens were procured at 1,2,4,6,8 and 12 weeks,the results of VEGF immunohistochemistry were observed.Results ①By 1 to 2 weeks after surgery,callus was not discerned by X-ray,the postive VEGF expressions were only detected in soft tissue;②By 4 to 6 weeks after surgery,external callus and circular callus were discerned by X-ray,the postive VEGF expressions were peak at external surface and osteosynthesis sites,the interior VEGF expressions appeared positive;③By 8 to 12 weeks after surgery,the fractures entirely unioned and new medullary cavities appeard by X-ray,the postive VEGF expressions decreased in mature callus,but the interior cells of transplants amply expressed positive.Conclusions VEGF is involved in the process of creeping substitution and related highly to the blood regeneration in the cortex.The time of revascularization is different in different sites of allogenic cortical transplants