骨折愈合过程中血管内皮生长因子及其受体的表达

Vascular endothelial growth factor and its receptor expression in fracture healing

目的 探讨血管内皮生长因子 (VEGF)在骨折愈合中的表达规律及其受体在骨折端血管内皮细胞内的表达类型。 方法 采用新西兰大耳白兔 35只 ,随机为术后 8、2 4、72h ,1、3、5、8周 7个时相组每组 5只 ,制作左侧桡骨中段骨折模型 ,按分组于相应时相点取骨折端标本固定 ,脱钙处理后行冰冻切片 ,利用原位杂交、免疫组织化学方法分别检测VEGF及其受体在骨折端的表达情况。 结果 在伤后 8h～ 8周的骨折部位发现 ,不同时间多种组织细胞参与表达VEGFmRNA及VEGF。在伤后 8h～ 8周的骨折端血管内皮细胞内检测到VEGF的flt1受体表达 ,1～ 3周为表达的高峰期 ;骨折后 3d～ 3周检测到flk1受体的强阳性表达。 结论 VEGF及其flt1受体表达贯穿于骨折愈合的始终 ,flk1受体在伤后一定时间呈强阳性表达。由于VEGF通过与其受体的特异性结合而发挥作用 ,因此可以确定VEGF在骨折后的血管重建过程中起重要作用 。

Objective To study the expression and changes of regularity of VEGF in the process of fracture healing, and what kind of EGF receptors are expressed in the endothelial cells of blood vessels in the fracture site. Methods The fracture models were made in the middle of rabbits, left radius, then the specimens in the fracture site after 8 hours, 24 hours, 72 hours and 1, 3, 5, 8 weeks were taken, fixed and decalcified. Freezing slices were made to detect the expression of VEGF and its receptor in the fracture site. Results VEGF mRNA and VEGF were detected in many kinds of cells in the fracture site during 8 hours to 8 weeks after fracture. Flt1 receptor of VEGF was found in the endothelial cells of blood vessel in the fracture site during 8 hours to 8 weeks after fracture, and high expression of flk1 receptor was detected during 3 days to 3 weeks after fracture. Conclusions The expression of VEGF and flt1 receptor run through the process of fracture healing, the maximal expressional period of them is from 1 to 3 weeks, flk1 receptor is highly expressed in a definite period after fracture. Because VEGF produces its effect through specific integration with its receptors, VEGF is definitive and important in the process of blood vessel rebuilding after fracture.