功能矫形前伸下颌对大鼠咬肌TrkB表达影响的研究

The changes of TrkB expression in masseter muscles of rats after functional mandibular advancement

目的:探讨功能矫形前伸大鼠下颌对青春期大鼠咬肌酪氨酸激酶受体-B(Tyrosine kinase receptor-B,TrkB)表达的影响。方法:将40只4周龄雄性SD大鼠随机分为实验组和对照组各20只,实验组大鼠佩戴自制的上颌功能矫治器,对照组不戴,分别在实验第3、7、14、21 d处死大鼠,通过免疫组织化学染色和RT-PCR检测两组大鼠咬肌中TrkB及其mRNA的表达。结果:实验3 d组、7 d组免疫组化阳性染色和mRNA的表达虽有增强,但与对照组相比,均无明显变化;实验14 d组、21 d组TrkB免疫组化阳性染色明显强于对照组,其mRNA表达结果亦同样高于对照组。结论:随着功能矫形前伸下颌时间的延长,TrkB表达含量逐渐增加,TrkB参与了咬肌在下颌前伸中的适应性改建活动。

Objective：To investigate the changes of Tyrosine kinase receptor-B（TrkB）expression in masseter muscles fibers of adolescent rats after functional mandibular advancement.Method：Forty 4-week-old male Sprague-Dawley（SD） rats were randomly divided into experimental and control groups.The mimic functional appliances were used in experimental groups,and the rats of two groups were killed on 3rd,7th,14th,21th day.Immunohistochemistry staining method and reverse transcription polymerase chain reaction（RT-PCR）were used to detect the TrkB expression of muscle fibers in rat masseter muscles.Result：The expression of TrkB in 3d-and 7d-groups in experimental groups were higher than that in control groups,but made no significance,the expression of TrkB were significantly higher in experimental 14d-and 21d-groups than that in control 14d-and 21d-groups.Conclusion：Accompanying the functional orthopedics,TrkB expression is progressively increased,which may contribute to the proprioceptive adaptation to masseter muscles rebuilding.