不同力下大鼠磨牙牙周膜血小板衍生生长因子BB时空表达研究

Expression of PDGF-BB in the Rat Periodontal Ligamemt in Response to the Different Occlusal Force

目的研究大鼠磨牙牙周膜中血小板衍生生长因子BB(platelet-de rived growth factor-BB,PDGF-BB)在力改变时的表达变化及其意义。方法建立8周龄雄性SD大鼠力丧失和力过载的动物模型,采用免疫组织化学的方法检测在实验12h及3、7、14、30d牙周膜细胞中PDGF-BB表达的动态变化。结果 PDGF-BB在力过载磨牙近远中牙周膜中表达逐渐增强,7d时信号最强,为72.78±6.90,14d后表达显著减弱至42.84±9.53;力丧失后3d牙周膜细胞中PDGF-BB表达显著增强,7d时表达最强,为66.10±11.61,14d后逐渐恢复正常表达水平。结论 PDGF-BB在牙周膜改建过程中的表达变化与力变化密切相关,提示临床上治疗有牙周疾病的患牙时,为了取得长期稳定的疗效,应更多地考虑力的影响。

Objective To study alteration of the expression level of PDGF-BB in rat periodontal ligament in Response to the different occlusal force to clarify the physiological role（s） of this protein in the ligament.Methods A model of overload of the occlusal force was established,which the occlusal surface on the upper first molar of 8-week-old male SD rats was approximately 1 mm elevated unilaterally;Another model was established,which the upper first molar was extracted to removed occlusal force against the lower first molar.The rats were perfusion-fixed on on 12 h,3 d,7 d,14 d and 30 d after treatment.The prepared sagittal sections were processed to study the expression of PDGF-BB in rat periodontal ligament by immunohistochemistry.Results Following the bite-raising,the number and the density of the positive cells of PDGF-BB in the periodontal ligament of the lower first molar increased gradually.The expression of PDGF-BB was the strongest on the 7th day 72.78±6.90.Compared to the normal rats,the expression level of PDGF-BB in the periodontal ligament of lower first molar significantly decreased on the 14th day 42.84±9.53.When occlusal force was removed the expression level of PDGF-BB in the periodontal ligament of the lower first molar showed a ra gradual increase,a more significant increase 66.10±11.61 was detected on the 7th day after occlusal force was removed.Subsequently,a gradual decrease was recognized.Conclusion The result of expression of PDGF-BB in the peridontal ligament suggests that PDGF-BB may play important roles in the process of peridontal ligament remodeling in response to the different occlusal force.