大鼠动情周期不同阶段正畸牙移动速度差异机制的研究

A bio-mechanism study of differential orthodontic tooth moving speed during the estrous cycle

目的探讨正畸牙移动对雌激素和胰岛素样生长因子(IGF)表达的影响,从体内实验角度阐明月经周期和应力对局部骨改建的影响机制。方法建立在Wistar雌性大鼠动情周期不同阶段给予正畸加力的实验模型,采用放射免疫、免疫组织化学和原位杂交等方法检测雌性大鼠动情周期不同阶段血清雌激素和牙周组织中的雌激素及IGF mRNA的表达变化。采用SPSS 11.0软件包对数据进行统计分析。结果正畸牙移动使处于动情周期不同阶段的雌性大鼠血清和牙周组织中的雌激素及牙周组织中的IGF mRNA表达增加,其中血清、牙周组织中的雌激素和IGF-Ⅰ的表达均表现为在动情期最低,动情前期最高;而IGF-Ⅱ的表达在动情周期没有明显规律。结论牙周组织中的雌激素及IGF参与了正畸牙移动引起的牙周组织改建,牙齿移动速度与月经周期密切相关。

Objective The purpose of this article was to investigate the changes of the estrogen and insulinlike growth factors （IGF） level induced by orthodontic tooth movements in order to elucidate the bio-mechanism of orthodontic treatments during the estrous cycle. Methods A Wistar rat experimental model was established to apply orthodontic activation during different stages of estrous. The serum and periodontal tissue estradiol level were determined by radioimmunoassay and immunohistochemistry. In situ hybridization was also used to detect the variation of the IGF mRNA expression in the periodontal tissues. The data of each group was analyzed with SPSS 11.0 software package. Results Both serum and periodontal estradiol level were increased by orthodontic activation during various stages of the estrous. IGF mRNA expression were also enhanced with the same trend. The estradiol and IGF-Ⅰ level showed in a similar pattern during the estrous cycle and the rhythm was not changed by the orthodontic activation. There was no rhythm of IGF-Ⅱ expression found in the estrous cycle. Conclusion It was concluded that estrogen and IGF were involved in the remodeling activities induced by the orthodontic activation. The speed of the orthodontic tooth movements was closely related to the estrous cycle.