不同强度50 Hz脉冲电磁场促进大鼠颅骨成骨细胞矿化成熟最佳参数的筛选

为研究不同强度脉冲电磁场(pulse electromagnetic fields，PEMFs)对大鼠颅骨成骨细胞（rat skull osteoblasts，OB）增殖及成熟矿化的影响,将大鼠颅骨成骨细胞随机分为 7 组. 检测大鼠颅骨成骨细胞的增殖，细胞内碱性磷酸酶（ALP）活性变化，细胞沉积钙盐的情况，组织化学染色以及成骨细胞内标志性分子表达量的改变.结果显示,0.6 mT组促细胞增殖作用最强（P <0.01）；0.6 mT、1.8 mT、3.0 mT和3.6 mT均能提高ALP活性，其中0.6 mT ALP活性最高（P＜0.01）；在磁场处理4 ～12 d时细胞沉积钙盐逐渐增加，6种强度的脉冲电磁场均能促进钙盐沉积，尤以0.6 mT水平最高； ALP 染色、茜素红染色0.6 mT 组均显著高于对照组（P<0.01）；0.6 mT组 Bmp-2和Collagen-1 mRNA 的表达明显（P<0.01）高于对照组，磁场处理组Rankl mRNA 的表达均比对照组低. 0.6 mT 50 Hz 脉冲电磁场是促进成骨细胞增殖和矿化成熟的最佳参数，这为采用脉冲电磁场治疗骨质疏松症提供了治疗参数的基础支持.

Screening 50 Hz Pulsed Electromagnetic Fields of Different Intensities on Proliferation,Differentiation and Mineralization of Rat Osteoblast for the Optimal Parameters

To study the effects of pulsed electromagnetic fields (PEMFs) of different intensities on proliferation, differentiation and mineralization potentials of rat osteoblast (OB), osteoblast cells were sub-cultured and randomly divided into seven groups: 0, 0.6, 1.2, 1.8, 2.4, 3.0, and 3.6 mT, respectively (with a 0.6 mT increment interval). MTT result showed that treatment at 0.6 mT, 1.8 mT and 3.6 mT induced a signifcant increase of osteoblast proliferation. Treatment at 0.6 mT signifcantly increased osteoblast proliferation (P<0.01). Treatments at 50Hz 0.6 mT signifcantly increased alkaline phosphatase (ALP) activity and the amount of calcium deposition (P<0.01) than that in control groups. The osteoblasts increased the formation of calcified tubercle from 4 days to 12 days after PEMFs exposure. Treatments at 50 Hz 0.6 mT significantly increased the amount of calcium deposition (P<0.01). Consistently, treatment at 0.6 mT signifcantly increased the number and area of histochemically stained (P<0.01), as well as alizarin red-stained ALP compared to the untreated control. mRNA expression showed that exposure at 0.6mT signifcantly increased Bmp-2 and Collagen-1 mRNA expression compared to the untreated control (P<0.01). Exposure to PEMFs of different intensities signifcantly decreased Rankl mRNA expression compared to the untreated control. Exposure at 50 Hz 0.6 mT PEMFs significantly enhanced osteoblast proliferation, differentiation and mineralization. It is a theoretical basis that pulsed electromagnetic fields were used to treat osteoporosis.