大鼠正畸牙牙周膜中增殖细胞核抗原表达的研究

Expression of proliferating cell nuclear antigen in rats′ periodontal ligament during orthodontic tooth movement

目的通过观察大鼠正畸牙移动过程中牙周膜内增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)的表达变化,探讨正畸过程中细胞增殖变化的机制。方法选用幼年SD大鼠,建立正畸牙移动模型,分别在加力后24 h、3 d、5 d、7 d、14 d、21 d处死动物,制备标本。进行免疫组化分析。结果对照组大鼠牙周组织中增殖细胞核抗原弱表达,实验组牙周膜中张力侧增殖细胞核抗原24 h时表达上调,3、5 d达最顶峰,7 d后逐渐下调,21 d趋于正常。结论正畸力促进牙周组织中细胞增殖,从而完成牙周组织的改建。

Objective To investigate the changes of proliferating cell nuclear antigen（PCNA） in rats＇ periodontal ligament in ortho- dontic tooth movement and the mechanism of changes of PCNA during orthodontic tooth movement. Methods Young SD rats were used to build up orthodontic movement models. The animals were sacrificed 23, hours ,3 days ,5 days ,7 days, 14 days and 21 days after continuous mechanical stress was applied. The expression of PCNA was performed by immunohistochemistry. Results Expression of PCNA in rats＇ periodontal ligament was weak in the control group. In the experimental group, the expression of PCNA on the tension side of periodontal ligament got stronger 24 hours after continuous mechanical stress, strongest 3 and 5 days after continuous mechanical stress ,weaker 7 days after the stress, and normal 21 days after the stress. Conclusions Orthodontic treatment promotes cell prolifera- tion in periodontium, and completes reconstruction of periodontium.