摘要
目的通过对去势大鼠股骨骨折模型愈合早期骨痂的组织学、骨密度以及转化生长因子β1(Transforminggrowthfactorbeta1,TGF-β1)、碱性成纤维细胞生长因子(basicfibroblastgrowthfactor,bFGF)、骨形态发生蛋白-2(bonemorphogeneticproteins-2,BMP-2)合成变化的观察,探讨骨质疏松骨折早期愈合过程的变化。方法将60只雌性SD大鼠分为去势组和对照组,3个月后制成股骨干骨折模型,伤后不同阶段处死,分别进行组织学、骨密度以及TGF-β1、bFGF、BMP-2免疫组化染色方法观察。结果大鼠去势后3个月全身骨密度检查证实去势组骨质疏松形成。骨折后第3d两组均开始形成原始骨痂;第4～6周,去势组骨痂比对照组少,且软骨痂比例较高,骨密度较低。免疫组化染色显示,在两组间bFGF、BMP-2的表达与分布、高峰出现与持续时间差异无显著性。去势组骨小梁附近表达TGF-β1的成骨细胞数目减少。结论骨质疏松使大鼠骨折早期骨痂的数量与质量降低,自软骨性骨痂至骨性骨痂演变过程减缓,对骨折愈合过程的影响与BMP-2、bFGF的表达无明显关联。TGF-β1在成骨细胞中的表达减少可能是引起骨质疏松骨折愈合质量下降的因素之一。
Objective The research was to observe the changes of histomorphology,bone mineral density of callus and the expression and distribution of transforming growth factor beta(TGF-β 1 ),basic fi-broblast growth factor(bFGF)and bone morphogenetic proteins-2(BMP-2)in osteoporotic fracture so as to evaluate the influence of osteoporosis on fracture healing process.Methods An osteoporotic animal model was established by ovariectomy in sixty SD rats,in which the femur was osteotomized by a wire saw as frac-ture healing model,internal fixed with a Kirschner pin three months after ovariectomy.The rats were scari-fied in3days,1,2,4and6weeks after operation,the callus formation was monitored over a6weeks period by histological and immunohistochemistry assessment.Results The status of osteoporosis in ovariectomy group was confirmed by total body bone mineral density measurement 3months after ovariectomy.The aver-age body weight of ovariectomy animals was337.8g compared to286.2g in the control group(P<0.01).The mean total body bone mineral density of ovariectomy group was0.162g /cm 2 and significant lower than0.187g /cm 2 of the control group.Primary callus came into formation in both groups3days after fracture.A reduction in fracture callus diameter and bone mineral density in the healing femur of the ovariectomy rats was observed on3to4weeks after fracture as compared with the control group.The histomorphological analysis revealed that the rate of soft fracture callus in the ovariectomy rats was more than that of the control rats.The immunohistochemical results showed that there were no significant difference of expression and distribution of BMP-2and bFGF between the ovariectomy and control group.A decrease of expression of TGF-β 1 from the osteoblasts close to the trabecular bone was observed.Conclusion Osteoporosis influences the quantity and quality of callus during the early period of fracture healing and reduces mineralization of soft callus.The failure of the osteoporotic rats to heal promptly is not due to lack of expression of BMP-2and bFGF;the decreased expression of TGF-βin osteoblasts may be the cause of decreased quality of os-teoporotic facture healing.
出处
《中华骨科杂志》
CAS
CSCD
北大核心
2003年第7期439-443,共5页
Chinese Journal of Orthopaedics
