桥连上皮带在唇腭部发育过程中的作用及意义探讨

The function of the bridging epithelium in the development of lip and palate

目的:研究上颌突、中鼻突之间的桥连上皮带在唇腭部发育过程中的作用。方法:将受精的白来航鸡蛋孵化到适当的H-H(hamburger and hamilton)阶段,分别进行:组织学切片、胚胎扫描电镜摄片、Brd U细胞增殖和TUNEL细胞凋亡实验。结果:鸡胚发育的H-H 24阶段,上颌突、中鼻突以及侧鼻突之间的上皮层相互靠近;H-H 26、27阶段,融合之前相邻突起之间的上皮细胞出现丝状伪足化,开始形成两两突起之间的桥连上皮带,之后桥连上皮带内细胞增殖减少,并出现了大量圆形凋亡细胞;H-H 28阶段:桥连上皮带在相邻突起融合过程中逐渐凋亡,相邻突起最终完全融合。结论:上颌突、中鼻突之间的桥连上皮带通过形成丝状伪足相互连接,桥连上皮带内细胞增殖减少、凋亡增加,这一系列变化在胚胎唇腭部的发育过程中起到了重要的作用。

Objective： To explore the function of the bridging epithelium between maxillary process and nasal process in the development of lip and palate. Methods： The fertilized white leghorn chick eggs incubated to the appropriate Hamburger and Hamilton（ HH） stages were examined by tissue histologic studies,scanning electron microscopy observation,Brd U assay and TUNEL assay respectively. Results： At H-H stage 24,the epithelia between maxillary,lateral nasal and globular process were juxtaposed. At H-H stage 26-27,string-like filopodia appeared and the bridging epithelium formed,then in the bridging epithelium cell proliferation was decreased and the apoptotic cells appeared. At H-H stage 28,the apoptosis of the bridging epithelium cells increased,the full fusion of the processes was completed. Conclusion： The occurrence of bridging epithelium between maxillary process and nasal process plays an important role in the development of lip and palate.