牙周炎大鼠正畸牙齿移动中牙周组织内MMP-8的表达变化

Variation of MMP-8 expression in periodontal tissues in rats with periodontitis during orthodontic tooth movement

目的探讨在正畸力作用下,炎性牙周组织和正常牙周组织内MMP-8的表达。方法选取6~8周健康雄性SD大鼠55只(体重200~250 g)。随机分为三组,其中5只大鼠不做任何处理作为空白对照组,正常加力组25只(对照组),炎性加力组25只(实验组)。建立实验性牙周炎模型4周后,去除牙周刺激物,对两组分别施加50 g正畸力牵大鼠上颌第一磨牙向近中移动。加力后第1 d、3 d、5 d、7 d、14 d两组各处死5只大鼠。采用免疫组化和定量分析方法观测各组大鼠牙周组织中MMP-8表达。结果空白对照组牙周组织内MMP-8表达较少。在牙周受压后,实验组3d、5 d、7 d、14 d,牙周组织内MMP-8的表达与对照组比较,第一磨牙近中压力侧牙周组织中MMP-8表达强度高,差异有统计学意义(P<0.05或0.01),并且MMP-8的表达在第5天时达到峰值。结论正畸力和炎症刺激物均可导致MMP-8的表达。MMP-8在大鼠牙周组织的改建中起调节作用。

Objective To investigate the expression of MMP-8 in the normal and inflammatory of periodontal tissue in rats underwent orthodontic force. Methods Sixty-eight healthy male Sprague-Dawley rats（ weighing 200 ~ 250 g） were selected. They were randomly divided into three groups,of which 5 rats without any treatment as a blank control group,25 rats with normal force as a control group,and 25 rats with inflammatory force as an experimental group. After establishing experimental periodontitis model for 4 weeks,the periodontal irritants were removed and 50 g orthodontic forces were applied respectively to the maxillary first molars. On the 1 d,3 d,5 d,7 d and 14 d after operation,5 rats in each group were sac-rificed. Immunohistochemistry and quantitative analysis were adopted to measure the expression of MMP-8 in the periodontal tissue. Results The expression of MMP-8 in the periodontal tissue of the blank control group was less than that in the periodontal tissue. After periodontal compression,the expression of MMP-8 in periodontal tissues was higher in the experimental group than in the control group on the 3 d,5 d,7 d and 14 d. The expression of MMP-8 in the periodontal tissue of the mesial pressure side of the first molar was high. The difference was statistically significant（ P〈 0. 05 or 0. 01）,and the expression of MMP-8 peaked on the 5 d. Conclusions Orthodontic force as well as inflammatory stimulus can evoke the expression of MMP-8. MMP-8 plays a regulatory role in the reconstruction of periodontal tissue in rats.