功能矫形前伸下颌对青春期大鼠咬肌TrkC表达的影响

目的探讨功能矫形前伸下颌对青春期大鼠咬肌酪氨酸激酶受体-C(tyrosine kinase receptor-C,TrkC)表达的影响。方法设立实验组与同步对照组,实验组大鼠佩戴功能矫治器,根据佩带周期分为实验3、7、14、21d组与正常同步对照组。采用免疫组织化学染色法及聚合酶链反应(PCR)检测大鼠咬肌TrkC及其mRNA的表达。结果与对照组相比,实验3、7d组,咬肌纤维TrkC免疫阳性染色与mRNA表达均无明显变化,而实验14、21d组TrkC免疫阳性染色明显强于同步对照组,TrkC基因表达亦明显高于对照组。结论功能矫形下颌前伸可致大鼠咬肌TrkC的表达发生改变,提示其参与了下颌前伸过程中咬肌适应性的改建活动。

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

Objective To investigate the changes of tyrosine kinase receptor-C(TrkC) expression in masseter muscle fibers of adolescent rats after functional mandibular advancement. Methods Forty 4-week-old Sprague-Dawley rats were randomly assigned to experimental 3 d-,7 d-,14 d-and 21 d-groups and control groups,respectively.The functional appliances were used only in the experimental groups.Immunohistochemical staining method and polymerase chain reaction(PCR) were used to detect TrkC expression of muscle fibers in rat masseter muscles. Results The TrkC-like immunoreactivity and the expression quantity of TrkC in 3 d-and 7 d-groups were not different from those in control groups,but were significantly higher in experimental 14 d-and 21 d-groups than in control 14 d-and 21 d-groups. Conclusion The functional mandibular advancement can change the expression of TrkC in masseter muscles of adolescent rats,which may contribute to the proprioceptive adaptation to muscle rebuilding.