失神经状态下胫骨骨折断端骨痂成骨的组织学变化

Histological changes of callus osteogenesis at tibial fracture site in denervated rats

背景:有研究表明神经系统在骨折的修复重建中发挥重要的作用,但其具体机制尚未阐明,中枢神经及神经生长因子对骨痂中成骨的影响至今少有报道。目的:观察失神经状态下胫骨骨折断端骨痂成骨的组织学变化。方法:用SD大鼠建立左胫骨闭合骨折髓内固定大鼠模型,建模成功后随机为3组,左胫骨骨折组;T10脊髓横断组:于左胫骨骨折后,横断切除T10段脊髓约0.3cm,制成T10脊髓完全性损伤大鼠胫骨骨折模型;神经生长因子治疗组:建立T10脊髓完全性损伤大鼠胫骨骨折模型后,肌注神经生长因子。术后各组均用苏木精伊红染色法观察骨组织形态变化,骨钙素免疫组织化学法观察骨痂中成骨情况,透射电镜观察成骨细胞内微结构变化。结果与结论:T10脊髓横断组大鼠在失神经状态下,骨痂中成骨细胞的数量减少,骨钙素表达减少,成骨细胞内细胞器功能低下。神经生长因子治疗组的以上各组织学观察指标均较T10脊髓横断组均有不同程度的改善。结果显示,神经生长因子可部分改善脊髓横断失神经状态下的骨组织再生情况。

BACKGROUND:Previous study showed that nervous system plays an important role in the fracture reconstruction.However,the concrete mechanism has not been totally expounded yet.The effect of central nervous and nerve growth factor on callus was rarely reported.OBJECTIVE:To observe histological changes of callus osteogenesis at tibial fracture site in denervated rats.METHODS:SD rats were prepared for closed fracture with left tibial intramedullary fixation models and were randomly assigned into 3 groups:Simple left tibial fractures group,T10 spinal cord transaction group:Based on the tibial fracture models,0.3 cm T10 spinal cord was transected and removed.Nerve growth factor group:Based on the frontal models,intramuscular injecting nerve growth factor.The morphological changes of bone tissues were observed by hematoxylin-eosin staining.The condition of osteogenesis in callus was observed by osteocalcin immunohistochemistry and the microstructure of osteoblasts was detected under a transmission electron microscope.RESULTS AND CONCLUSION:The osteoblasts quantity was decreased,osteocalcin decreased and osteoblasts organelle functions lowered in the T10 spinal cord transaction group.Compared with the T10 spinal cord transaction group,these indexes in the nerve growth factor group were improved.The findings demonstrated that nerve growth factor can partly improve bone tissue regeneration in denervate state.