Objective: This research aimed to investigate the expression of osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) in mandibular distraction osteogenesis (DO) regulated by parathyroid hormone (PTH) and to explore the mechanism by which PTH promotes DO.
Methods: A rabbit mandibular DO model was established. The rabbits were randomly divided into experimental group and control group. The former were subcutaneously injected with different doses of PTH on alternate days, the latter was injected with normal saline every other day. Serum OPG levels were detected through enzyme-linked immunosorbent assay. The OPG and RANKL expression levels in the DO-induced formation of a new bone tissue were examined through immunohistochemistry staining.
Results: The serum OPG levels gradually increased during distraction. At the end of the stretch, the OPG expression in the experimental group was significantly stronger than that in the control group. As the fixed period was extended, the OPG expression in the new bone gradually decreased, but the RANKL expression increased.
Conclusion: Intermittent subcutaneous PTH injection can upregulate the OPG expression and accelerate bone metabolism. Thus, this procedure promotes the early generation of a new bone in the mandible through DO.
目的: 研究甲状旁腺激素（PTH）调控下颌骨牵张成骨中骨保护素（OPG）和核因子κB受体活化因子配体（RANKL）的表达，探讨PTH促进牵张成骨的作用机制。
方法: 建立兔下颌骨牵张成骨模型，随机分为实验组和对照组。实验组隔日皮下注射不同剂量PTH，对照组隔日皮下注射生理盐水。酶联免疫吸附法检测血清中OPG的水平，免疫组织化学法研究OPG、RANKL在下颌骨牵张成骨新骨中的表达。
结果: 在牵张期血清OPG水平逐渐升高；在牵张结束时，实验组OPG表达最强，与对照组比较差异有统计学意义。随固定期的延长，OPG的表达逐渐下降，而RANKL的表达逐渐增强。
结论: 间隙性皮下注射PTH可上调OPG表达，加速骨代谢，促进下颌骨牵张区新骨生成。