血管内皮生长因子在卵巢切除大鼠骨折愈合骨痂中的表达

背景：血管内皮生长因子在骨折愈合过程中起着重要作用，研究发现去卵巢大鼠影响骨折愈合，但其作用机制尚未明确。 目的：观察去卵巢大鼠股骨骨折愈合中骨痂组织学变化以及血管内皮生长因子的表达与分布，探讨骨质疏松对大鼠骨折修复的影响与血管内皮生长因子对其的作用。 方法：取12周龄雌性Sprague-Dawley 大鼠20只，随机分成假手术组和去卵巢组。制造股骨骨折模型，于术后4周处死，各组截取大鼠右侧股骨标本后行计算机X射线摄像仪摄片观察骨折愈合情况，并应用双能X射线骨密度仪测量右股骨骨密度，苏木精-伊红染色观察骨痂生长情况及其组织形态，免疫组织化学染色测定血管内皮生长因子表达。 结果与结论：骨折后4周，去卵巢组形成的骨痂中含有的软骨骨痂比例高与假手术组。去卵巢组中表达血管内皮生长因子的成骨细胞数目少于假手术组。提示骨质疏松大鼠骨折愈合形成的骨痂质量较差，血管内皮生长因子在成骨细胞中的表达减少是骨质疏松骨折愈合质量下降的可能因素之一。 关键词：骨质疏松；骨折愈合；血管内皮生长因子；雌激素；组织构建；组织工程

Expression of vascular endothelial growth factor in callus during fracture healing in ovariectomized rats

BACKGROUND: Vascular endothelial growth factor (VEGF) plays an important role in fracture healing. Researches have demonstrated that ovariectomy affects bone healing, but the mechanisms remain poorly understood. OBJECTIVE: To observe the changes of histomorphology and the expression of VEGF in callus during fracture healing and to explore the effects of VEGF on fracture healing in osteoporotic rat fracture. METHODS: Twenty 12-week-old female Sprague-Dawley rats were divided randomly into sham-operated and ovariectomized groups. Fracture models of rat were established. All rats were sacrificed at 4 weeks after operation. Right femora were removed for radiological observation and for the monitoring of bone mineral density by dual-energy X-ray absorptiometry. The bone callus growth and its histology were examined by haematoxylin-eosin staining. The expression and changes in the level of VEGF were examined by immunohistochemical staining. RESULTS AND CONCLUSION: Histomorphological analysis revealed a higher content of soft fracture callus in the ovariectomized rats than that in the sham-operated group. The immunohistochemistry results showed a decrease of expression of VEGF from the osteoblasts in the callus of the ovariectomized rats than that in the sham-operated group at 4 weeks after fracture. The results revealed that lower quality of callus forms during the early period of osteoporotic fracture healing. The decreased expression of VEGF may be a reason of decreased quality of osteoporotic fracture healing.