Wang Yao, Li Qijia, Sun Ruijun, Wang Zhiqiang, Bai Junging
Department of Rehabilitation, the Second Hospital of Tangshan, Tangshan Hebei, 063000, P.R. China.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2010 Feb;24(2):230-4.
To investigate the expression levels and significance of vascular endothelial growth factor (VEGF) and microvessel density (MVD) in rabbit radius defects repaired with allogeneic and autogenic bone.
Forty adult New Zealand rabbits were chosen, and 10 mm bone defect model was created in the bilateral radii of 28 experimental rabbits. The other 12 rabbits provided allogeneic bone under the standard of American Association of Tissue Bank. In the left side, allogeneic bone were used to repair bone defect (experimental group), equal capacity autogenous iliac bone was used in the right side (control group). Animals were sacrificed at 2, 4, 8, and 12 weeks postoperatively. Immunohistochemical method was used to determine the expression of VEGF, CD34 protein and MVD counting. Bone histomorphometric parameters, including percent trabecular area (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), and trabecular separation (Tb.Sp) were measured by von Kossa staining undecalcified slices. The relation was analyzed between VEGF and MVD, histomorphometric parameters.
The positive signals of VEGF protein were detected in cytoplasm of vascular endothelial cells, chondrocytes, osteoblasts, fibroblasts and osteoclasts. At 2 weeks, there was no significant difference in VEGF protein expression between experimental group and control group (P > 0.05); at 4 and 8 weeks, the expression of VEGF in control group was significantly higher than that in experimental group (P < 0.05); and at 12 weeks, there was no significant difference between two groups (P > 0.05). There was a positive correlation (P < 0.01) between VEGF expression and MVD value in two groups at 2, 4, 8, and 12 weeks postoperatively. There was no significant difference in bone histomorphometric parameters (BV/TV, Tb.Th, Tb.N, Tb.Sp) between two groups at 12 weeks postoperatively (P > 0.05), but there was a positive correlation between VEGF expression and parameters of BV/TV, Tb.Th, and Tb.N (P < 0.01); and a negative correlation between VEGF and Tb.Sp (P < 0.01).
VEGF can express diversity at different time and positions, and the different expressions indicated various biology significances in the process of the bone healing. It can coordinate growth of cartilage and bone and profit vascular reconstruction of allogeneic bone. VEGF may participate in promoting osteogenesis in the course of allogeneic bone transplantation.
探讨血管内皮生长因子（VEGF）和微血管密度（MVD）在同种异体骨和自体骨修复兔桡骨缺损中的表达水平及意义。
选取40只成年新西兰兔，对28只实验兔双侧桡骨制作10 mm骨缺损模型。另外12只兔按美国组织库协会标准提供同种异体骨。左侧用同种异体骨修复骨缺损（实验组），右侧用等量自体髂骨（对照组）。术后2、4、8和12周处死动物。采用免疫组织化学方法检测VEGF、CD34蛋白表达及MVD计数。通过von Kossa染色不脱钙切片测量骨组织形态计量学参数，包括骨小梁面积百分比（BV/TV）、骨小梁数量（Tb.N）、骨小梁厚度（Tb.Th）和骨小梁间距（Tb.Sp）。分析VEGF与MVD、组织形态计量学参数之间的关系。
VEGF蛋白阳性信号在血管内皮细胞、软骨细胞、成骨细胞、成纤维细胞和破骨细胞的胞质中被检测到。术后2周，实验组和对照组VEGF蛋白表达无显著差异（P>0.05）；4周和8周时，对照组VEGF表达明显高于实验组（P<0.05）；12周时，两组间无显著差异（P>0.05）。术后2、4、8和12周两组VEGF表达与MVD值呈正相关（P<0.01）。术后12周两组骨组织形态计量学参数（BV/TV、Tb.Th、Tb.N、Tb.Sp）无显著差异（P>0.05），但VEGF表达与BV/TV、Tb.Th和Tb.N参数呈正相关（P<0.01）；VEGF与Tb.Sp呈负相关（P<0.01）。
VEGF在不同时间和部位表达具有多样性，其不同表达在骨愈合过程中具有不同生物学意义。它可协调软骨和骨的生长，有利于同种异体骨的血管重建。VEGF可能参与促进同种异体骨移植过程中的成骨作用。
