恒定磁场中大鼠成骨细胞的增殖和功能活性

背景：磁场对成骨细胞生物学的影响存在一定的分歧。目的：探讨不同强度恒定磁场作用不同时间后成骨细胞增殖和功能活性的改变。方法：用体外培养的SD大鼠成骨细胞第3～5代分别在0,5,22,86,135mT恒定磁场下培养,观察8,12,24h后细胞增殖和凋亡变化及细胞上清液中骨钙素及Ⅰ型前胶原C端前肽的表达。结果与结论：磁场作用8,12h后,5,22,86,135mT磁场培养的细胞增殖指数均高于对照组（P〈0.05）,作用24h时,仅5mT组高于对照组（P〈0.05）。而0,5,22,86,135mT恒定磁场下培养8,12,24h的凋亡百分数差异无显著性意义。磁场作用8h后,22,86,135mT组骨钙素分泌量均高于对照组（P〈0.05）;作用24h后,135mT组骨钙素分泌量则明显低于对照组（P〈0.05）;而磁场作用8,12h后,22,86mT组Ⅰ型前胶原C端前肽分泌量明显高于对照组（P〈0.05）,作用24h后,135mT组Ⅰ型前胶原C端前肽分泌量则明显低于对照组（P〈0.05）。表明低强度磁场、短时间作用可促进成骨细胞的增殖及成骨物质的分泌,而高强度磁场或磁场暴露时间过长则抑制成骨细胞增殖及成骨物质的分泌。

Effect of static magnetic field on proliferation and functions of rat osteoblasts

BACKGROUND：The effect of magnetic field on osteoblast biology remains poorly understood.OBJECTIVE：To evaluate the effect of the static magnetic field（SMF） with different intensities and exposure time on the proliferation,apoptosis and function of osteoblasts.METHODS：Passage 3-5 Sprague-Dawley rat osteoblasts cultured in vitro were exposed to 0,5,22,86,135 mT SMF for 8,12 and 24 hours.Cell proliferation and apoptosis changes and osteocalcin and carboxyterminal propeptide of typeⅠprocollagen（PICP） in the cell supernatant were determined.RESULTS AND CONCLUSION：After exposure to 5,22,86,135 mT SMF for 8,12 hours,cell proliferation index was significantly higher compared with the control group（P 0.05） ,and after exposure to SMF for 24 hours,the cell proliferation index was significantly higher only in the 5 mT SMF group than in the control group（P 0.05） .There was no significant difference in percentage of apoptotic cells after 0,5,22,86,135 mT SMF exposure at 8,12 and 24 hours.After exposure to SMF for 8 hours,osteocalcin level in the 22,86 and 135 mT SMF groups was significantly higher than that in the control group（P 0.05） .After exposure to SMF for 24 hours,osteocalcin level in the 135 mT group was significantly lower than that in the control group（P 0.05） .After exposure to SMF for 8,12 hours,PICP level was significantly higher in the 22,86 mT SMF groups than in the control group（P 0.05） .After exposure to SMF for 24 hours,PICP level was significantly lower in the 135 mT SMF group than in the control group（P 0.05） .These findings suggest that short-time low-intensity magnetic field promotes the proliferation of osteoblasts and the secretion of osseous substance,while high-intensity magnetic field or long-time magnetic field exposure inhibits the proliferation of osteoblasts and the secretion of osseous substance.