周期性牵张面颌致成肌细胞内Ca2+浓度变化的研究

目的观察牵张引起的成肌细胞内Ca2+浓度变化,探求口腔正畸功能矫形治疗中肌肉改建机制。方法采用四点弯曲加力装置,使体外培养的SD大鼠面颌部成肌细胞发生牵张变形后,测定加力后不同时段及在镜下给予乙酰胆碱(Ach)后成肌细胞内Ca2+荧光强度的变化。结果牵张引起的成肌细胞内Ca2+荧光强度的升高明显高于Ach的作用,并且在经历了体外的牵张加力后,Ach刺激并未使成肌细胞内Ca2+荧光强度出现预先设想的叠加效果,在各个不同的实验组中Ca2+荧光强度反而略有下降。结论牵张引起的骨骼肌细胞内Ca2+浓度升高的机制不同于肌肉兴奋收缩耦联过程中出现的Ca2+浓度升高,Ca2+作为第二信使引发的细胞内各种结构和功能蛋白的改变可能参与了肌肉改建过程。

Changes of intracellular calcium of cultured myoblast induced by cyclic stretch

Objective To elucidate the effects of stretch and acetylcholine on the intracellular calcium of myoblast and study the remodeling reaction of muscle in a variety of mechanical environments.Methods Myoblasts from maxillofacial skeletal muscle of one week old male Sprague-Dawley rats were cultured and stretched cyclicly using a four-point bend device.Fluo-3 as the Ca~(2+) indicator was used to determine the intracellular calcium concentration.Acetylcholine was added to the cultured liquid under the microscope.Results The elevation of the intracellular calcium induced by stretch was significantly higher than induced by acetylcholine and there was no additional effect on the intracellular calcium when acetycholine was applied to the stretched myoblast.Conclusion The results suggested calcium as a signal molecule was involved in the muscle remodeling process induced by stretch.