中文摘要：

目的究不同大小机械牵张力对成骨细胞增殖能力及碱性磷酸酶（ALP）活性的影响，以了解牙槽骨改建机制。方法 通过自行研制的多通道细胞牵张应力加载系统对小鼠成骨样细胞MC3T3-E1同时施加0％、6％、12％和18％的机械牵张力，作用24h和48h后，用MTT法检测细胞受力后的增殖变化，ALP试剂盒检测ALP的变化。结果细胞受力后，其增殖能力随牵张力值的增大而明显增强（P〈0．01），而ALP活性随牵张力值的增大明显降低（P〈0．01）。结论不同大小机械牵张力可以影响成骨细胞的增殖能力及ALP活性，与力值大小密切相关。

英文摘要：

Objective To investigate the effects of different magnitudes of mechanical strain on proliferation and alkaline phosphatase （ALP） activity in mouse osteoblast-like cells （MC3T3-E1）. Methods MC3T3-E1 cells were subjected to 0%, 6%, 12%, 18% elongation for 24h and 48h by using multi-passage cell stress loading system respectively. MTT colorimetric method was used to assess the proliferation of the cell, ALP activity was detected by AI.P assay kit. Results The proliferation of MC3T3-E1 cells was increased significantly 24h and 48h after mechanical strain treatment concomitant with increasing stretching force （P〈0. 01）, but ALP activity was decreased significantly （P〈0. 01）. Conclusion Different magnitudes of mechanical strain can affect the proliferation and ALP activity of MC3T3-E1 cells . Their proliferation and ALP activity depend on magnitude of mechanical strain.