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Effects of ELF magnetic field and induced currents on cell growth or differentiation of cultured osteoblasts.

ELF磁场和感应电流对培养成骨细胞的细胞生长或分化的影响。

基本信息

批准号：
10837010
负责人：
YAMAGUCHI Hisao
金额：
$ 2.05万
依托单位：
The University of Tokushima
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

项目摘要

We have obtained some research results from the experiments for the effects of exposure to ELF magnetic fields(3mT) as following.(1) Significant differencies existed between the exposure and control groups of cultured osteoblasts(MC3T3 E-1) as to cellular ALP activities and protein contents at 30 and 60 Hz during the application of magnet for 25 days, respectively. The stimulatory effects of 60 Hz magnetic fields for protein synthesis of osteoblasts were observed concerning the accumulation of collagen and non-collagen protein in the cultures for 14 days in particularly.(2) No significant differences were observed between the exposure and control groups on the accumulation of collagen and non-collagen protein due to the electric currents at 60 Hz during 25 days.(3) The effects of exposure to ELF magnetic field for short time on growing or differentiated osteoblasts.1) The intracellular Ca2+ concentration ([Ca2+]i) of growing osteoblasts after addition of bradyknin(BK) in the culture media with or without of Ca2+ were examined. The [Ca2+]i increased instantly from the resting level on addition of BK, reaching a maxmal value in normal medium with Ca2+. When the free Ca2+ was chelated in the culture medium by addition of EGTA, the peak value was only half of that in normal medium after the stimulation of BK. Exposure to magnetic field for 24 hours 4t the absence of Ca2+ strongly inhibited the increase in [Ca2+]i.2) The intracellular Ca2+ concentration [Ca2+]i of growing osteoblasts after addition of endothelin-1(ET) in the culture media with or without of Ca2+ were examined. [Ca2+]i of unexposed cells increased instantly by addition of ET, but the increasing of [Ca2+]i in exposed cells by reagent was inhibited significantly as BK treatment. When the differetiated cells were exposed to magnetic field, the increasing of [Ca2+]i by ET stimulation was accelerated significantly in contrast to the growing cells.

本实验研究了超低频磁场对成骨细胞(MC3T3E-1)细胞碱性磷酸酶(ALP)活性和蛋白质含量的影响，结果表明：(1)在磁场作用25天时，细胞ALP活性和蛋白含量在30和60赫兹的频率下与对照组有显著差异。观察了60 Hz磁场对成骨细胞蛋白质合成的刺激作用，尤其是培养14天后胶原蛋白和非胶原蛋白的积累。(2)60 Hz磁场作用25天，对胶原和非胶原蛋白的积累无明显影响。(3)短时间暴露于ELF磁场对成骨细胞生长或分化的影响。1)在有无钙离子的培养液中加入缓激肽(Bradynin，BK)后，观察成骨细胞内钙离子浓度([Ca~(2+)]i)。加入BK后，细胞内[Ca~(2+)]i即刻升高，在含Ca~(2+)的正常培养液中达到最大值。加入EGTA对培养液中的游离钙离子进行络合时，BK刺激后，其峰值仅为正常培养液的一半。磁场作用24小时后，无Ca~(2+)强烈抑制成骨细胞内[Ca~(2+)]_i的升高。2)在有或无Ca~(2+)的培养液中加入内皮素-1(ET)后，观察细胞内[Ca~(2+)]_i的变化。加入ET后，未暴露细胞[Ca~(2+)]i即刻升高，而BK处理可显著抑制试剂引起的细胞内[Ca~(2+)]i升高。当分化细胞暴露于磁场中时，ET刺激的细胞内[Ca~(2+)]i升高速度明显快于生长细胞。