经颧弓后上牵引下颌后髁突软骨中PTHrP的表达及意义

Expression of PTHrP in the condyle cartilage after traction of the mandibular ramus and zygomatic arch in rabbits

目的:观察经颧弓后上牵引下颌后兔颞下颌关节髁突软骨中PTHrP的分布特征,探讨PTHrP在髁突软骨改建过程中的作用。方法:手术在颧弓和下颌角之间放置弹簧持续地将兔右侧下颌骨向后上方牵引,分别于术后2、4、6周处死动物,观察实验组与对照组PTHrP的分布特征。结果:经颧弓后上牵引下颌,髁突受到过度负荷后髁突软骨发生改建。经颧弓后上牵引2周,增殖层和上肥大层软骨细胞PTHrP表达明显增强,而4和6周PTHrP表达强度不均,软骨细胞丛附近软骨细胞前体细胞内PTHrP表达较强。对照组PTHrP在整个实验过程中均处于弱表达。结论:PTHrP可能与髁突软骨的修复性改建密切相关。

Objective：To understand the roles of PTHrP in the pathogenesis of temporomandibular joint after over mechanical loading. Methods：Fifteen adult New Zealand rabbits were subjected to traction between the mandibular ramus and zygomatic arch in the postero-superior direction unilaterally using elastic force. The rabbits were killed respectively at 2, 4 and 6 weeks and the histologic changes were observed by Hematoxylin ＆ Eosin staining. The expression of PTHrP in the condyle of TMJ was observed by immunohistochemistry. Results： Stronger expression of PTHrP could be found in proliferation cell layers and upper hypertrophy cell layers in the early stage after operation, and weaker expression in mid stage, but stronger near the chondrocyte clusters. Conclusion： It is suggested that PTHrP might relate to the regeneration of condyle cartilage.