摘要
目的研究咬合创伤时犬牙周组织中神经生长因子(nerve growth factor,NGF)及其酪氨酸蛋白激酶受体A(tyrosine ki-nase A,trkA)mRNA表达水平的变化,探讨咬合创伤致口面痛的可能机制.方法高出咬合面1.5 mm的镍铬合金嵌体黏固于18只杂种犬右侧上颌第一、二磨牙咬合面的Ⅰ类洞形内,造成对(牙合)牙的创伤.黏固嵌体后3、7、14、30、60 d时拔除双侧上下颌磨牙并立即刮取牙周膜组织.用逆转录(RT)-PCR检测牙周膜组织中NGF及trkA mRNAs表达水平并与无咬合创伤的对照组作比较.结果①咬合创伤3 d起,创伤侧牙周组织内NGF mRNA急剧升高,14～30d时表达水平最高,30d时NGF mRNA是对照侧及对照组的3.0倍,60d时表达量下降.3～7d对照侧牙周组织NGF mRNA也上调(P＜0.05).②trkA mRNA表达水平的变化规律同NGF mRNA,trkA mRNA在30 d时表达水平最高.③观测时间内,创伤侧NGF和trkA mRNAs的表达水平高于对侧(P＜0.01),分别从咬合创伤3 d和7 d起高于对照组(P＜0.05).结论咬合创伤能导致牙周膜内NGF及trkA mRNA表达水平上调.单侧咬合创伤能导致双侧牙周组织NGF、trkA mRNA表达水平的改变.
Objective To detect NGF mRNA and trkA mRNA in dogs＇ periodontal tissues in order to study the orofacial pain mechanisms induced by traumatic occlusion. Methods The occlusal surface of the right first and second maxillary molars in 18 dogs were unilaterally raised 1.5 mm with the casting Ni-Cr inlay which were fixed in Class I inlay hole. On the 3rd,7th, 14th,3Oth and 60th days after teeth operations, the upper and lower molars in two-side dentition were extracted. Periodontium tissue was detached from root cementum. NGF and trkA mRNAs were detected by using RT-PCR in experimental and control groups. Results ① NGF mRNA expression up-regulated from the 3rd to 30th days compared with the control group （ P 〈 0.05） and reached peak level during 14 to 30 days after traumatic occlusion was induced. Compared with contralateral side and control group, NGF mRNA was about three-fold on day 30 in trauma periodontium ligament. An upregulation expression of NGF mRNA in contralateral sides was also observed during 3 to 7 days. ②trkA mRNA expression was similar to that of NGF mRNA and had the highest level on the 30th day after teeth operation. ③NGF and trkA mRNA at the trauma periodontium side was stronger than that at the contralateral side and control group （ P 〈 0.01）. Conclusion The present study shows that NGF and trkA mRNAs are increased in traumatic occlusal periodontal tissue. A unilateral occlusion initiates nerve responses in the whole molar dentition. NGF maybe plays an important role in orofacial pain caused by traumatic occlusion.
出处
《口腔医学》
CAS
2005年第4期216-218,共3页
Stomatology
