交变应力对大鼠翼外肌成肌细胞形态学改建的影响

目的 评价不同交变应力作用下大鼠翼外肌成肌细胞的形态学改建，从而探讨矫形治疗中成肌细胞的改建机制。方法 在自行研制脉动式细胞力学系统基础上，将大鼠翼外肌成肌细胞在膜交变应力培养小室内培养并进行鉴定，分别施加2.5 kPa、5.0 kPa和10.0 kPa交变力学刺激，于加力后6 h和12 h用倒置相差显微镜观察细胞形态学变化。结果 成肌细胞形态在交变应力加载前后由无规律延伸向与张应力平行方向上转化；在较低的应变水平（2.5 kPa、5.0 kPa）作用下成肌细胞排列方向主要沿张应变方向，而在较大的应变水平（10.0 kPa）作用下成肌细胞排列方向具有较多的沿张应变垂直方向变化的趋势。结论 不同的交变应力对大鼠翼外肌成肌细胞形态学改建具有一定的影响，在一定范围内的交变应力可以促进成肌细胞在二维方向的排列。

Time Varied Stress Effects on the Shape-alteration of Myoblast in Rats

Objective  To investigate the effects of time varied stress on the shape-alteration of myoblast in rats and to provide a theoretic base to determine the mechanics of myoblast in orthodontic therapy. Methods  Based on the pulsatile mechanical system our group founded, this study loaded different strain（2.5 kPa、5.0 kPa and 10.0 kPa） to the myoblast of lateral pterygoid muscle. The alterations in shape under time varied stress of 6 h and 12 h were assessed by phase-contrast microscopy, scanning electron microscope. Results  The orientation of myoblast seemed no obvious orderliness before loading. But after loading the lower time varied strain（2.5 kPa, 5.0 kPa）, they were changed their orientation to paralel with the direction of strain along with the membrane. Meanwhile, there had one trend to set the shape of myoblast more upright along with the membrane after loading the higher time varied stress（10.0 kPa）. Conclusion  It was proved that the different time varied stress in vitro expressed the different influence on the remolding of myoblast.