成骨细胞移植促进老龄鼠骨质疏松性骨折愈合过程中VEGF的动态变化

目的：动态观察在幼龄成骨细胞移植促进骨质疏松性骨折愈合过程中，VEGF在不同时相的表达及其生物学意义。方法：通过建立老龄骨质疏松SD大鼠骨折的动物模型，并将体外培养的SD雄性乳鼠成骨细胞移动到SD雌性鼠老年骨质疏松性骨缺损部位，利用免疫组化及原位杂交检测骨折愈合过程中不同时间相的移植标本VEGF、VEGFmRNA的表达，并作图像分析、绘出其动态变化图。结果：实验组VEGF、VEGFmRNA均在7d左右可见有阳性表达的细胞，14d有分泌,高峰其中以软骨细胞中阳性最强，21 d分泌量开始下降，56d后基本消失。而对照且未见明显分泌高峰。结论；成骨细胞细胞促进老龄鼠骨质疏松性骨折愈合，其机制可能是通过促进VEGF的转录和表达，从而促进骨折部位建立良好的血液循环，加速骨形成。

Activity of vascular endothelial growth factor during the process of osteoblast grafts to accelerate fracture healing in osteoporotic rats

Objective\ To study the biological function and behavior of vascular endothelial growth factor (VEGF)during the process of osteoblast grafts to accelerate fracture healing in osteoporotic rats.Methods Fracture models of osteoporotic rats were set up and osteoblast grafts were performed.Immunnohistochemistry was used to detect the expression of VEGF during different periods of fracture healing, in situ hybridization was used to study the expression of VEGF mRNA,and image analysis was done.Results\ In the experimental group,VEGF was positive 7 days after osteoblast grafting,and there was peak secretion of chondrocytes about 14 days post transplantation,which began to decline at 21 days,and disappear at 56 days.In contrast,there was no peak secretion in the control group.Conclusion\ VEGF not only plays an important role in bone formation,but also enhances blood circulation in fractured site.It can accelerate fracture healing in osteoporotic rats.