骨质疏松骨折愈合中软骨细胞凋亡与血管内皮生长因子的表达

目的：探讨骨质疏松骨折愈合过程中血管内皮生长因子(VEGF)的表达变化及其与软骨细胞凋亡发生的关系。方法：建立SD大鼠骨质疏松股骨骨折模型，分别于骨折后1、2、3、4w取材进行HE染色及VEGF免疫组化染色，并用TUNEL法和琼脂糖凝胶电泳法检测细胞凋亡。，结果：在骨折后第1w，间充质细胞未见VEGF表达；第2、3w时软骨细胞VEGF反应呈强阳性；第4w其表达强度开始下降。骨折愈合的不同时期都有软骨细胞凋亡的发生，第3w表现最为明显。结论：VEGF在骨折的第2w表达最强，到第3、4w开始下降。软骨细胞的凋亡主要发生在骨折后的第3w。VEGF可能直接与软骨细胞凋亡发生有关。

Expression of VEGF and apoptosis of chondrocytes during osteoporotic fracture healing

Objective: To study the expression of VEGF and apoptosis of chondrocytes during the osteoporotic fracture healing. Methods: An experimental model of the osteoporotic fracture healing on rat femurs was used. The expression of VEGF were determined by means of immunohistochemistry and the apoptosis of chondrocytes was detected by TUNELmethods and agarose gel eletrophoresis at the different stages of healing. Results: VEGF was expressed in chondrocytes and osteoblasts at first week after fracture. There were no expression of VEGF in mesenchymal cells. On the second, third week after fracture, VEGF was strongly expressed in chondrocytes. During the fourth week, the expression of VEGF began to decrease. There were apoptosis of chondrocytes during whole fracture healing. Apoptosis of chondrocyte peaked during the third week. Conclusion: The levels of VEGF is different at different periods of the osteoporotic fracture healing. VEGF may take part in forming of blood vessels and participate in inducing the apoptosis.