卵巢去势对骨折愈合超微结构和BMP-4基因表达的影响

目的:探索雌激素对骨折愈合超微结构和骨形态发生蛋白-4(BMP-4)基因的定位分布的影响.方法:选用健康SD大鼠,随机分为卵巢切除(OVX)组和假手术对照(S)组.制成胫骨骨折愈合模型并分别于骨折后不同时间点处死取材.通过电镜观察超微结构变化;采用原位杂交方法研究卵巢去势对BMP-4基因表达影响.结果:(1)OVX组在骨痂形态及成骨细胞和破骨细胞活性与S组比较有明显差异;(2)骨折后1～3d BMP-4m RNA表达强度:S组＜OVX组.结论:雌激素缺乏时,骨转换加快,从而BMP-4表达增多.雌激素在骨折愈合过程中起重要作用.

Effects of ovariectomy on ultrastructure and BMP-4 gene expression during fracture healing

Objective:To study the effects of ovariectomy on ultrastructure and expression of BMP-4 in tibia fracture healing.Method:Ninty-six female SD rats were divided randomly into ovariectomy group (OVX),Sham-operation group(S).One month later closed fractures were made manually in shafts of both tibias and intra-medullary fixed.Calluses and soft tissue were collected at the date of 1 st ,3 rd ,5 th ,7 th ,14 th ,28 th ,56 th ,112 th after fracture.The activity of osteoblasts and osteoclasts was observed by electron microscope according to the different times.The regularity of BMP-4 expression on osteoporotic fracture and the effect of estrogens on it was studied by in situ Hybridization with BMP-4 cDNA probe.Result:(1)OVX group was different with S group in callus density and arrange of trabecular bone,activity of osteoblasts and osteoclasts.(2)From 1 to 3 days after fracture,the signals of BMP-4 were positively detected,and S was weaker than OVX( P <0.01).Conclusion:When estrogen deficient,bone turnover is enhanced with BMP-4 gene expression increasing.Estrogens play an important role in fracture healing.