雌激素对骨质疏松大鼠骨折愈合过程成骨细胞血管内皮生长因子表达的影响

目的研究雌激素对骨质疏松大鼠骨折愈合过程成骨细胞血管内皮生长因子表达的影响,进一步了解雌激素对骨代谢的作用机制。方法采用80只20月龄的雌性大鼠,将其随机分为对照组和实验组,每组40只,麻醉下制作左股骨骨折模型,术后实验组每隔1d注射1次雌激素,分别于1、2、3、4周取骨痂,利用免疫组织化学染色法、原位杂交方法检测成骨细胞血管内皮生长因子(VEGF)的表达,利用骨矿分析仪测定骨痂的密度。结果 VEGF在骨折部位被多种细胞表达,且成骨细胞最明显,其表达强度随时间变化而变化,3周左右达到高峰,实验组比对照组表达更明显,实验组骨痂密度高于对照组(P<0.05)。结论雌激素可促进成骨细胞VEGF的表达,VEGF是雌激素调节骨代谢的机制之一,可促进骨质疏松骨折的愈合。

Effects of estrogen on osteoblast vascular endothelial growth factor expression during bone fracture healing in osteoporotic rats

Objective To study the effects of estrogen on osteoblast vascular endothelial growth factor expression during bone fracture healing in osteoporotic rats, and to further understand the mechanism of estrogen on bone metabolism. Methods Eighty female rats, 20 months old, were randomly divided into control group and experimental group （n=40 each）. Left femoral fracture models were established under anesthesia. Rats in experimental group underwent estrogen injection every two days after operation. Callus at 1, 2, 3 and 4 weeks were respectively obtained. Immunohistochemistry staining and in-situ hybridization were used to detect VEGF expression in osteoblasts, and bone densitometer was used for detecting callus density. Results VEGF was expressed in a variety of cells at the fracture site, especially in osteoblasts. The expression intensity changed over time, peaking around the third week. In experimental group, expression was more obvious and callus density was higher than those of control group （P〈0.05）. Conclusion Estrogen may promote osteoblast VEGF expression, which in turn, as part of estrogen regulated bone metabolism, may promote healing of osteoporotic fracture.