不同年龄组大鼠正畸力作用下龈沟液中基质金属蛋白酶的表达

Expression of MMPs in gingival crevicular fluid of the rats in different age groups with orthodontic appliances

目的:观察2个年龄组大鼠牙受正畸力后龈沟液中基质金属蛋白酶-1(matrix metalloproteinase-1,MMP-1)和基质金属蛋白酶-9(matrix metalloproteinase-9,MMP-9)含量的变化。方法:选择6周龄和12周龄雌性Wistar大鼠各20只,采用粘结剂联合磨沟固位法在上颌安装正畸加力装置,牵引一侧上颌第一磨牙向近中,另一侧作为对照侧。每周提取大鼠实验牙及对照牙的龈沟液,应用SDS-PAGE、Western印迹和Gel-Doc凝胶成像系统定量检测龈沟液中MMP-1与MMP-9含量的改变。采用SPSS11.0软件包对实验各周龈沟液中MMP-1和MMP-9的含量进行方差分析。结果:6周龄组大鼠和12周龄组大鼠龈沟液中MMP-1及MMP-9含量的基础水平以及在加力第1周时的水平无统计学差异(P>0.05),但12周龄组比6周龄组稍高。加力早期,12周龄组大鼠MMPs含量增长速度快于6周龄组;后期,12周龄组大鼠较6周龄组大鼠的MMPs含量下降速度慢。结论:12周龄大鼠受正畸力后,龈沟液中MMPs的表达较6周龄组高,12周龄大鼠较6周龄大鼠的正畸牙根吸收可能更严重。

PURPOSE： To detect the changes of MMP-1 and MMP-9 in gingival crevicular fluid （GCF） of the rats in different age groups with orthodontic appliances. METHODS： 40 female Wistar rats were selected as the animal model, in which there were 20 6-week-old rats and 20 12-week-old rats. The orthodontic appliances were fixed onto the maxilla of the rats after general anesthesia. The maxillary first molar in the experimental side was drawn mediaUy by applying an excess force of 50g, with both of the maxillary central incisors as anchorage. In the control side, the maxillary first molar was winded around the dental cervix with ligature wire. The GCF was collected every week, and MMP-1 and MMP-9 were assayed in quantitation by SDS-PAGE, Western blot and Gel Doc quantitative analysis system,respectively. The data were analyzed for ANOVA using SPSS11.0 software package. RESULTS： No statistical difference of the original concentration of MMP-1 and MMP-9 in GCF was found between adolescent group and adult group （P〉0.05）, but the adult group＇s contents were a little more than adolescent group＇s, and is the same as the 1st week＇s content. The concentration of MMPs in adult group changed more greatly than that in adolescent group. At the beginning of the experiment, the MMPs＇ increasing speed of adult group was higher than that of adolescent group. But at the end, the rate of descent of adult group was lower than that of adolescent group. CONCLUSIONS： The expression of MMPs in gingival crevicular fluid of adult rats is higher than that of adolescent rats. It may be more serious of the orthodontic root resorption in adult rats than in adolescent rats. Supported by Shandong Provincial Natural Science Foundation （Grant No.Y2007C023） and Jinan Science and Technology Development Plan （Grant No.200705089-9）.