关键词: 先天性腭裂, 胚胎, 电镜观察

Abstract: BACKGROUND AND AIM: To observe the ultrastructure of embryonic palate cells during cleft palate formation using the model of congenital cleft palate. MATERIALS AND METHODS: The model of congenital cleft palate was induced in NIH mice by intraperitoneal injection of dexamethasone on GD12.5. The control group was raised under the same condition except the injection of dexamethasone. The mice was sacrificed by cervical dislocation on GD13.5,GD14.5 and GD15.5. The fetal mice were removed and the heads were cut for light and electron microscopic studies.The embryonic palate and the palatal cells were examined by SEM and TEM during the process of the palate development and congenital cleft palate formation. RESULTS: In the control group, with the embryonic development, the cleft was diminished, basal epithelial membrane was broken down, pieces of nuclear chromatin became marginated, excretion appeared in the MEE cell, the matrix was abundant between EPM cells, palatine shelves were fused completely on GD15.5. In the experimental group, palatine shelf grew slowly, and was smaller than the control group at the same time point, MEE cells on the palatine shelf surface were connected tightly yet with the development of palatine shelves, basal membrane remained intact, epithelial cell became multiplayer, cilia appeared on the cell surface, the matrix was less between EPM cells, the cleft was formed on GD15.5. CONCLUSION: The development and differentiation of embryonic palatal cells were affected after being exposed to dexamethasone, which was associated with cleft palate formation.

Key words: congenital cleft palate, embryo, electron microscope