Flt-1、Flk-1在人年轻恒牙和成熟恒牙牙髓表达的组织学研究

目的探讨人恒牙牙髓组织不同发育阶段血管内皮生长因子受体1（VEGFR-1/Flt-1）、血管内皮生长因子受体2（VEGFR-2/Flk-1）表达的组织学特征及其在人恒牙牙根发育成熟中的可能作用。方法将因正畸治疗需要而拔除的人健康前磨牙（无畸形中央尖、牙隐裂、过度磨耗等）分为根尖开放的年轻恒牙和根尖闭合的成熟恒牙,每组各15例,采用免疫组织化学方法检测Flt-1、Flk-1蛋白的表达与定位并进行图像采集,应用Image-ProPlus 6.0和SPSS 13.0对年轻恒牙和成熟恒牙牙髓组织Flt-1、Flk-1的阳性表达进行图像和统计学分析。结果 Flt-1、Flk-1在牙髓组织血管内皮细胞免疫反应阳性;年轻恒牙牙髓VEGF、Flk-1阳性表达的平均光密度值（OD）高于成熟恒牙（P〈0.05）,而Flt-1的表达低于成熟恒牙（P〈0.05）;Flt-1、Flk-1呈显著负相关性表达（P〈0.01）。结论年轻恒牙和成熟恒牙牙髓组织Flt-1、Flk-1呈现不同特征表达,提示Flt-1、Flk-1参与了牙根的发育过程,成熟恒牙牙髓防御修复能力下降可能与Flk-1表达不足有关。

Histological Study of Flt-1, Flk-1 in the Pulp of Young and Mature Permanent Teeth

Objective To investigate the expression and distribution of Flt-1 and Flk-1 in the pulp of young and mature permanent teeth,and to explore the role of Flt-1 and Flk-1 in the permanent root development.Methods Young and mature permanent teeth were collected for orthodontic reasons： The expression and localization of Flt-1 and Flk-1 were studied by immunohistochemistry and analyzed with Image-ProPlus 6.0 and SPSS 13.0.Results Immunohistochemical staining of Flt-1 and Flk-1 were detected in vascular endothelial cells.The expression of Flk-1 was more positive in young permanent teeth than in the mature teeth（P0.05）;while Flt-1 was more positive in the mature;the expression of Flt-1 and Flk-1 was negatively correlated with each other（P0.01）.Conclusion The expression of Flt-1 and Flk-1 in the pulp of young and mature permanent teeth shows different characteristics which suggests that Flt-1 and Flk-1 may play an important role in permanent tooth development and maturation.Inadequate expression of Flk-1 may lead to the poor defense and repair capacity of mature permanent teeth.