前导改变对大鼠颞下颌关节滑膜中iNOS及COX-2表达影响的研究

Expression of iNOS and COX-2 in Synovial Membrane of Rat with Altered Anterior Guidance

目的:探讨实验性前导斜度改变对大鼠颞下颌关节(temporomandibular joint,TMJ)滑膜中诱导型一氧化氮合成酶(iNOS)及环氧合酶-2(COX-2)表达的影响。方法:采用低速金刚砂轮打磨大鼠上下前牙,建立前导缺失模型。在大鼠上前牙粘结舌侧增大15°、30°金属冠,建立相应前导增大15°、30°模型;3、7、14、28d每组各取2只大鼠一侧TMJ及另一侧TMJ滑膜组织,免疫组织化学染色(immunohistochemistry,IHC)及实时定量聚合酶链反应(Real-time polymerase chain reaction,Real-time PCR)检测TMJ滑膜iNOS和COX-2的表达情况。结果:前导斜度增大30°组COX-2、iNOS表达较对照组显著增强(P<0.008)。其中COX-2在3d时表达最高,3、7d较28d有统计学差异(P<0.008)。iNOS在7d时表达最高,较3、14、28d表达无统计学差异。结论:iNOS及COX-2可能是前导异常造成颞下颌关节滑膜炎的重要分子机制之一。

Objective：To investigate effects of experimentally altered anterior guidance on the expression of cyclooxygenase-2（COX-2）and inducible nitric oxide synthase（iNOS）in temporomandibular joint synovium of rats.Methods：Anterior guidance deletion model was induced by eliminating the contact between anterior teeth in every direction with a diamond wheel.The anterior guidance accretion models were accomplished by cemented metal crowns which gained 15 and 30degree on palatal side to the incisors of rats＇ maxilla.Two animals in each group were sacrificed after 3,7,14,and 28 days.The complete TMJ of one side and TMJ synovium of the other side were obtained for analysis of iNOS and COX-2expression by immunohistochemistry（IHC）and real-time polymerase chain reaction analysis（real-time PCR）.Results：The anterior guidance in 30 degree group（group T3）showed statistical differences when compared with control group（group C）in COX-2and iNOS mRNA expression（P〈0.05）.In group T3,the level of COX-2reached the highest on day 3and there was statistical difference among specimens sacrificed after 3d,7dand 28d（P〈0.008）.iNOS expression peaked on day 7,but showed no statistical differences compared with those of day 3,14,and 28.Conclusion：COX-2and iNOS may be involved in TMJ synovitis caused by altered anterior guidance.