糖尿病大鼠牙齿移动后牙周组织基质金属蛋白酶-2表达的变化

目的探讨糖尿病大鼠正畸牙齿移动过程中基质金属蛋白酶- 2（MMP- 2）的分布和表达变化，研究糖尿病对牙周组织胶原代谢的影响。方法选用80只雄性SD大鼠, 牵引左侧上颌第一磨牙近中移动。实验组以链脲佐菌素腹腔注射制备1型糖尿病模型，3周后开始实验，分别于加力后0、3、7、14、21 d处死大鼠，应用两步免疫组化法检测大鼠牙周组织MMP- 2的表达。结果MMP- 2免疫组化结果显示牙齿移动后，牙周膜两侧MMP- 2表达增加，破骨细胞、骨细胞、成纤维细胞和部分成骨细胞MMP- 2染色阳性。图像分析结果显示实验组变化较对照组小。平均光密度表现动态变化，7 d最低，而后缓慢升高。加力后积分光密度逐渐升高，7 d达到顶峰，而后缓慢下降，21 d时仍维持在较高水平。结论未加力时，糖尿病大鼠颌骨胶原代谢增强。在正畸牙齿移动过程中，糖尿病大鼠骨质反应能力降低，胶原代谢较弱，牙齿移动时MMP- 2呈规律性变化，与牙齿正畸骨改建关系密切，在牙齿移动中起着重要的作用。

Change of Expression of Matrix Metalloproteinase-2 in the Periodontal Tissues of Diabetes Mellitus Rats during Orthodontic Tooth Movement

OBJECTIVE: To observe the expression and distribution of matrix mentallproteinase-2 (MMP-2) in the periodontal tissues of diabetes mellitus (DM) rats during tooth movement, and to observe the affection of diabetes mellitus on the collagen metabolism. METHODS: Eighty male Sprague-Dawley rats were used. Mesial force was applied to pull the maxillary first molar. Forty rats were rendered diabetic by injection of streptozotocin. In 3 weeks after the injection, rats were subjected to lateral tooth movement. The animals were sacrificed after 0, 3, 7, 14 and 21 days respectively. Two-step immunohistochemical method was applied to localize and examine the expression of MMP-2 in periodontal tissue of rats. RESULTS: MMP-2 immunohistochemical results indicated that the MMP-2 expression increased and was observed on both sides periodontium of movement tooth, osteoclast, cementoblast, osteocyte, fibroblast and osteoblast appeared positive. According to the immunohistochemistry image analysis, experiment group changes was less obvious than control group. Dynamic changes of OD occured, reaching the minimum on the 7th day and then increasing slowly. IOD increased steadily, up to the peak on the 7th day, and then decreased, which still remained a high level on the 21st day. CONCLUSION: DM alveolar bone collagen metabolism increases. DM alveolar bone reactive potency decreases in orthodontic tooth movement, weak collagen metabolism. MMP-2's activity changes regularly, in close relation to bone remodeling, and plays an important role during the orthodontic tooth movement.