TNF—a在糖尿病合并牙周炎大鼠模型中的表达及意义

目的：建立糖尿病合并牙周炎大鼠模型，观察比较近牙槽嵴区牙周膜内肿瘤坏死因子-a（TNF-a）的含量，探讨高血糖对牙周组织炎症程度的影响。方法：糖尿病大鼠（STZ组）模型采用链脲佐菌素一次性腹腔注射制备，单纯牙周炎组州组）注射同剂量的枸橼酸钠缓冲液。成模且稳定后（4周），两组都采用大鼠牙颈部丝线结扎的方法诱导牙周炎模型，于结扎后1周，2周，3周处死大鼠，采用组织学方法，免疫组织化学结合MATLAB7．0．1图像灰度定量分析法，研究近牙槽嵴区牙周膜中TNF-a水平的变化及牙周组织炎症的进展程度。结果：N组与STZ组除0周外各时间点两组之间比较有显著性差异（P〈0．001）；N组内各时间点每两组之间比较有统计学差别（P〈0．05）；STZ组内各时间点每两组之间比较有统计学差别（P〈0．05）。随时间的增加，各组大鼠的炎症程度增加，TNF—a的表达水平增加，STZ组的病变进展程度显著重于N组。结论：一次性腹腔注射STZ＋牙颈部丝线结扎可成功建立实验性糖尿病大鼠的牙周炎模型。高血糖浓度使糖尿病大鼠牙槽骨TNF-a的表达水平增加，降低了机体的损伤一修复能力，牙周组织的炎症进一步加重。

Expression and Significance of TNF-a on the Rats with Diabetes and Periodontitis

Objective： To establish the experimental model of rats with periodontitis and diabetics and to investigate the effects of hyperglycemic on the severity of inflammation. Methods： The diabetics models were established by the streptozotocin and periodontitis models were captured by the silk thread. Then the histologic and the expression of TNF-a were observed and analyzed at the first week, the second week and the third week after the establishment of rats＇ model. Results： The level of TNF-a on the periodontium in the diaba- tes rats was higher than that of the non-diabetic one（P〈0.001）. There was statistically significant difference at every time point of group N （P 〈 0.05）. There was statistically significant difference of group STZ when compared between every two time-points （P 〈 0.05）. Conclu- sion： Diabetic rats of periodontitis model can be successfully established by intraperitoneal injection of STZ and tiring silk thread to teeth. In periodontal tissue the expression level of TNF-a increased due to high blood glucose levels. And its damage-repair ability was red- uced, and inflammatory periodontal tissue was aggravated.