牵张力作用下培养的人牙周膜成纤维细胞生成NO的实验研究

目的：观察在机械牵张力作用下牙周膜成纤维细胞NO的生成情况以及iNOS的表达情况。方法：用自行研制的细胞加载系统，对培养至第4代的人牙周膜成纤维细胞施以频率为每分钟6个周期（5s拉伸，5s松弛）、拉伸率为12％的牵张力，分别于加载后3，10，20，40，60min取上清液进行NO含量检测；以及于加载24，48，96h后固定细胞，进行iNOS免疫组化反应。结果：NO含量在所研究时间范围内逐渐增加；iNOS免疫组化结果显示iNOS的染色强度随着作用时间延长而增强。结论：牙周膜成纤维细胞在机械牵张力作用下合成NO增多，它可能通过合成和释放NO这一途径，在应力作用下的牙周组织改建过程中起作用。

Study of NO production of human periodontal ligament fibroblasts under mechanical strain

AIM: To observe the production of NO and expression of iNOS of human periodontal ligament fibroblasts (PDLFs) under mechanical strain. METHODS:PDLFs were stretched by 6 cycles/min(5 seconds stretching and 5 seconds relaxing). According to the previous experiment the tension strength to the PDLFs was only 12% of the force produced by self-producction cultured cell loading system. At experimental time point of 3,10,20,40,60min, the culture medium was harvested to examine the NO concentration. At experimental time point of 24,48,96 h, the PDLFs was fixed and iNOS immunocytochemical reaction was conducted. RESULTS: The NO concentration was enhanced and iNOS positive stain was intensified during experimental time range. CONCLUSION:NO production of human periodontal ligament fibroblasts was enhanced under mechanical strain, which indicated that the PDLFs played a role in the remodeling of periodontal tissue perhaps through the production and releasing of NO.