低频电磁刺激对成骨细胞生理功能的影响及其机制的研究
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摘要
目前电磁场刺激已被广泛应用于对骨折以及其他一些骨病的治疗,然而我们对电磁刺激作用于骨细胞的分子机制仍知之甚少。当前电磁刺激在医疗上的应用主要是根据临床经验而缺乏理论依据。因而近半个世纪以来,众多学者在该领域进行了大量的理论以及实验研究。然而,至今对于电磁场的生物学作用在科学界仍存在诸多争论。本文中,我们从理论和实验两方面对电磁刺激对于细胞胞浆钙离子以及膜电位影响进行了研究。我们采用成骨细胞作为模型来检验极低频电磁场能够改变胞浆钙离子浓度以及细胞膜电位的理论假设,并且对理论工作中所预言的窗口效应进行验证。本工作在以下两方面具有参考价值：第一,我们首次证明了极低频电磁场能够引起成骨细胞胞浆钙离子的响应,这为进一步研究电磁刺激作用于骨细胞的分子机制奠定了基础。第二,我们首次从理论和实验两方面证实了电磁刺激对于成骨细胞作用的窗口效应,并初步探寻了有效窗口,这对于电磁刺激的临床应用具有广泛的参考价值。
Electromagnetic fields (EMFs) are widely used in modern medicine to heal non-unions of bone fracture and treat some bone-related diseases. Nonetheless, the specific molecular mechanisms are not fully understood. In current, the application of EMF doses on treatment is largely dependent on clinical experiences, which lacks academic supports. Thus two aspects, theoretical and empirical researches, have been emphasized in this field for almost half a century. However, still there were controversies of electromagnetic effects within the scientific community. In this work, we studied the effects of electromagnetic fields on intracellular calcium and cell membrane potential from the perspective of both theoretical and experimental works. Osteoblastic cells were used as a model both to test the hypothesis that extremely low frequency (ELF) magnetic fields can alter the concentrations of the intracellular calcium and levels of membrane potential, and to examine the'window'effect predicted by the theoretical work. This work is valuable in two aspects. For one thing, it proves for the first time that ELF magnetic fields can induce the uptake of intracellular calcium levels in osteoblasts, which will contribute to the exploration of the molecular mechanisms of EMF effects on bone cells. For another, it provides an example for finding the quantitative map of EMF effects, which has a great reference value for clinical applications of EMF.
Electromagnetic fields (EMFs) are widely used in modern medicine to heal non-unions of bone fracture and treat some bone-related diseases. Nonetheless, the specific molecular mechanisms are not fully understood. In current, the application of EMF doses on treatment is largely dependent on clinical experiences, which lacks academic supports. Thus two aspects, theoretical and empirical researches, have been emphasized in this field for almost half a century. However, still there were controversies of electromagnetic effects within the scientific community. In this work, we studied the effects of electromagnetic fields on intracellular calcium and cell membrane potential from the perspective of both theoretical and experimental works. Osteoblastic cells were used as a model both to test the hypothesis that extremely low frequency (ELF) magnetic fields can alter the concentrations of the intracellular calcium and levels of membrane potential, and to examine the'window'effect predicted by the theoretical work. This work is valuable in two aspects. For one thing, it proves for the first time that ELF magnetic fields can induce the uptake of intracellular calcium levels in osteoblasts, which will contribute to the exploration of the molecular mechanisms of EMF effects on bone cells. For another, it provides an example for finding the quantitative map of EMF effects, which has a great reference value for clinical applications of EMF.
引文
[1]Harris S E, Guo D, Harris M A, et al. Transcriptional regulation of BMP-2 activated genes in osteoblasts using gene expression microarray analysis:role of Dlx2 and Dlx5 transcription factors. Front Biosci,2003,8:S1249-1265
[2]Karsenty G. Role of Cbfal in osteoblast differentiation and function. Semin Cell Dev Biol,2000, 11:343-346
[3]熊志立,孟繁浩,李遇伯等.成骨细胞的骨形成调控机制.生命的化学,2004,Vol.24(1)44-46
[4]Tenforde T S. Biological interactions of extremely low-frequency electric and magnetic fields. Bioelectrochem Bioenerg,1991,25:1-17
[5]Pilla A A. Weak time-varying and static magnetic fields:from mechanisms to therapeutic applications. In:Stavroulakis P, eds. Biological effects of electromagnetic fields:mechanisms, modeling, biological effects, therapeutic effects, international standards, exposure criteria. Berlin: Springer,2003.352-394
[6]Liboff A R, Cherng S, Jenrow K A, et al. Calmodulin-dependent cyclic nucleotide phosphodiesterase activity is altered by 20 microT magnetostatic fields. Bioelectromagnetics, 2003,24:32-38
[7]Kindzelskii A L, Petty H R. Ion channel clustering enhances weak electric field detection by neutrophils:apparent roles of SKF96365-sensitive cation channels and myeloperoxidase trafficking in cellularresponses. Eur Biophys J,2005,35:1-26
[8]Otter M W, McLeod K J, Rubin C T. Effects of electromagnetic fields in experimental fracture repair. Clin Orthop Relat Res,1998,355:S90-104
[9]Liboff A R. Geomagnetic cyclotrone resonance in membrane transport. J Biol Phys,1985a,13: 99-102
[10]Pilla A A. Electrochemical information and energy transfer in vivo. In:Proceedings of seventh IECEC. Washington:American Chemical Society,1972.761-764
[11]McLeod K J, Rubin C T, Donahue H J. Electromagnetic fields in bone repair and adaption. Radio Sci,1995,30:233-244
[12]Schimmelpfeng J, Dertinger H. Action of a 50Hz magnetic field on proliferation of cells in culture. Bioelectromagnetics,1997,18:177-183
[13]Lednev V V. Possible mechanism for the influence of weak magnetic fields on biological systems. Bioelectromagnetics,1991,12:71-75
[14]Binhi V N. Interference ion quantum states within a protein explains weak magnetic field effects in biosystems. Electromagnetobiology,1997,16:203-214
[15]Gartzke J, Lange K. Cellular target of weak magnetic fields:ionic conduction along actin filaments ofmicrovilli. Am J Physiol Cell Physiol,2002,283:C1333-1346
[16]Bawin S M, Adey W R, Sabbot I M. Ionic factors in release of 45Ca2+ from chicken cerebral tissue
by eletromagnetic field. Proc Natl Acad Sci USA,1978,75 (12):6314-6318
[17]Adey W R. Cell membranes:the electromagnetic environment and cancer promotion. Neurochem Res,1988,13 (7):671-677
[18]Blackman C F. Influence of electromagnetic fields on the efflux of calcium ions from brain tissue in vitro:a three-model analysis consistent with the frequency response up to 510 Hz. Bioelectromagnetics,1988,9 (3):215-217
[19]陈树德,张红锋.低频电磁场对细胞生物效应的研究Chin J Phys Med,1998, Vol.20 (2): 78-80
[20]Lohmann C H, Schwartz Z, Liu Y, et al. Pulsed electromagnetic fields affect on phenotype and connexin 43 protein expression in MLO-Y4 osteocyte-like cells and ROS 17/2.8 osteoblast-like cells. J Orthop Res,2003,21(2):326-334
[21]李丽荣,罗二平,申广浩等.脉冲电磁场对体外培养成骨细胞的影响.中国医学物理学杂志,2005,Vol.22(1)：388-390
[22]Philips J L. Effects of electromagnetic field exposure on gene transcription. J Cell Biochem. 1993,51 (4):381-386
[23]Blank M, Goodman R. Do electromagnetic fields interact directly with DNA. Bioelectromagnetics,1997,18 (2):111-115
[24]Hartig M, Joos U, Wiesmann H P. Capaeitively coupled electric fields accelerate proliferation of osteoblast-like primary cells and increase bone extracellular matrix formation in vitro. Eur Biophys J,2000,29 (7):499-506
[25]Diniz P, Shomura K, Soejima K, et al. Effects of pulsed electromagnetic field (PEMF) stimulation on bone tissue like formation are dependent on the maturation stages of the osteoblasts. Bioelectromagnetics,2002,23 (5):398-405
[26]苏献双,张敏.电磁场促进骨形成的作用机制.口腔材料器械杂志,2005,Vol.14(2)：96-98
[27]Nagai M, Ots M. Pulsating electromagnetic fields stimulates mRNA expression of bone morphogenetic protein 2 and 4. J Dent Res,1994,73 (10):1601-1605
[28]Bodamyali T, Bhatt B, Hughes F J, et al. Pulsed electromagnetic fields simultaneously induce osteogenesis and upregulate transcription of bone morphogenetic proteins 2 and 4 in rat osteoblasts in vitro. Biochem Bioph Res Co,1998,250 (2):458-461
[29]Zhuang H, Wang W, Seldes R M, et al. Electrical stimulation induces the level of TGF-β1 mRNA in osteoblastic cells by a mechanism involving calcium/calmodulin pathway. Biochem Bioph Res Co,1997,237 (2):225-229
[30]Fitzsimmons R J, Strong D D, Mohan S, et al. Low-amplitude, low-frequency electric field-stimulated bone cell proliferation may in part be mediated by increased IGF-Ⅱ release. J Cell Physiol,1992,150(1):84-89
[31]Fitzsimmons R J, Ryaby J T, Mohan S, et al. Combined magnetic fields increase insuline-like growth factor Ⅱ in TE-85 human osteosarcoma bone cell cultures. Endocrinology,1995,136 (7): 3100-3106
[32]Lee J H, Mcleod K J. Morphologic responses of osteoblast-like cell in monolayer culture to ELF electromagnetic fields. Bioelectromagnetics,2000,21 (2):129-136
[33]Bersani F, Marinelli F, Ognibene A, et al. Intramembrane protein distribution in cell cultures is affected by 50 Hz pulsed magnetic fields. Bioelectromagnetics,1997,8 (7):463-469
[34]Chang K, Chang W H, Tsai M T, et al. Pulsed electromagnetic fields accelerate apoptotic rate in osteoclasts. Connect Tissue Res,2006,47(4):222-228
[35]Carson J J, Prato F S, Drost D J, et al. Time-varying magnetic fields increase cytosolic free Ca2+ in HL-60 cells. Am J Physiol,1990,259 (4 Pt 1):C687-C692
[36]Liburdy R P. Calcium signaling in lymphocytes and ELF fields Evidence for an electric field metric and a site of interaction involving the calcium ion channel. FEBS,1992,301(1):53-59
[37]Lindstrom E, Lindstrom P, Berglund A, et al. Intracellular calcium oscillations induced in a T-cell line by a weak 50 Hz magnetic field. J Cell Physiol,1993,156 (2):395-398
[38]Lyle D B, Fuchs T A, Casamento J P, et al. Intracellular calcium signaling by Jurkat T-lymphocytes exposed to a 60 Hz magnetic field. Bioelectromagnetics,1997,18 (6):439-445
[39]Sisken J E, DeRemer D. Power-frequency electromagnetic fields and the capacitative calcium entry system in SV40-transformed Swiss 3T3 cells. Radiat Res,2000,153 (5 Pt 2):699-705
[40]Shahidain R, Mullins R D, Sisken J E. Calcium spiking activity and baseline calcium levels in ROS 17/2.8 cells exposed to extremely low frequency electromagnetic fields (ELF EMF). Int J Radiat Biol,2001,77 (2):241-248
[41]Craviso G L, Poss J, Lanctot C, et al. Intracellular calcium activity in isolated bovine adrenal chromaffin cells in the presence and absence of 60 Hz magnetic fields. Bioelectromagnetics, 2002,23 (8):557-567
[42]Madec F, Billaudel B, Charlet de Sauvage R, et al. Effects of ELF and static magnetic fields on calcium oscillations in islets of Langerhans. Bioelectrochemistry,2003,60 (1-2):73-80
[43]Fitzsimmons R J, Ryaby J T, Magee F P, et al. Combined magnetic fields increased net calcium flux in bone cells. Calcif Tissue Int,1994,55:376-380
[44]Spadaro J A, Bergstrom W H. In vivo and In vitro effects of a pulsed electromagnetic field on net calcium flux in rat calvarial bone. Calcif Tissue Int,2002,70:496-502
[45]霍霞,徐锡金,陈耀文.激光扫描共聚焦显微镜荧光探针的选择和应用.激光生物学报,1999,Vol.8(2)：152-156
[46]Cain C D. Electromagnetic fields and signal transduction pathways. In:Brighton C T, Pollack S R, eds. Electromagnetic in Medicine and Biology. San Francisco:San Francisco Press,1991.61-65
[47]Luben R A. Effects of low-energy electromagnetic fields (pulsed and DC) on membrane signal transduction processes in biological systems. Health Physics,1991,61:15-28
[48]McLeod K J, Rubin C T. Observations from mechanically and electrically induced bone remodeling. In:Blank M, eds. Electricity and magnetism in biology and medicine. San Francisco: San Francisco Press,1993.98-700
[49]McLeod K J, Turner S, Rubin C T. Bone tissue adaption in response to high frequency mechanical perturbations. Ann Biomed Eng,1997,25 (S1):77
[50]Heermeier K, Spanner M, Trager J, et al. Effects of extremely low frequency electromagnetic field (EMF) on collagen type I mRNA expression and extracellular matrix synthesis of human osteoblastic cells. Bioelectromagnetics,1998,19:222-231
[51]Brighton C T, Wang W, Seldes R, et al. Signal transduction in electrically stimulated bone cells. J Bone Joint Surg Am,2001,83 (A10):1514-1523
[52]Diniz P, Soejima K, Ito G. Nitric oxide mediates the effects of pulsed electromagnetic field stimulation on the osteoblast proliferation and differentiation. Nitric Oxide,2002,7:18-23
[53]Goldbeter A, Dupont G, Berridge M L. Minimal model for signal-induced Ca2+ oscillations and for their frequency encoding through protein phosphorylation. Pro Natl Acad Sci USA,1990,87 (4):1461-1465
[54]Galvanovskis J, Sandblom J. Periodic forcing of intracellular calcium oscillators Theoretical studies of the effects of low frequency fields on the magnitude of oscillations. Bioelectrochemistry,1998,46:161-174
[55]Torres J J, Cornelisse L N, Harks E G, et al. Modeling action potential generation and propagation in NRK fibroblasts. Am J Physiol Cell Physiol,2004,287 (4):851-865
[56]Kusters J M, Dernison M M, van Meerwijk W P, et al. Stabilizing role of calcium storedependent plasma membrane calcium channels in action-potential firing and intracellular calcium oscillations. Biophy J,2005,89 (6):3741-3756
[57]Wong T K, Neumann E. Electric field mediated gene transfer. Biochem Bioph Res Co,1982,107 (2):584-587
[58]Lo M M S, Tsong T Y, Conrad M K, et al. Monoclonal antibody production by receptor-mediated electrically induced cell fusion. Nature,1984,310:792-794
[59]Mir L M, Orlowski S, Belehradek S. Electrochemotherapy potentiation of antitumour effect of bleomycin by local electric pulses. Eur J Cancer,1991,27 (1):68-72
[60]Adair R K. Biological effects on the cellular level of electric field pulses. Health Phys,1991,61 (1):395-399
[61]Fukuda E, Yasuda I. On the piezoelectric effect of bone. J Physiol Soc Jpn,1957,12:1158-1162
[62]Li J K, Lin J C, Liu H C, et al. Cytokine release from osteoblasts in response to different intensities of pulsed electromagnetic field stimulation. Electromagn Biol Med,2007,26 (3): 153-165
[63]Tsai M T, Chang W H, Chang K, et al. Pulsed electromagnetic fields affect osteoblast proliferation and differentiation in bone tissue engineering. Bioelectromagnetics,2007,28 (7): 519-528
[64]Selvamurugan N, Kwok S, Vasilov A, et al. Effects of BMP-2 and pulsed electromagnetic field (PEMF) on rat primary osteoblastic cell proliferation and gene expression. J Orthop Res,2007, 25(9):1213-1220
[65]Lohmann C H, Schwartz Z, Liu Y, et al. Pulsed electromagnetic field stimulation of MG63 osteoblast-like cells affects differentiation and local factor production. J Orthop Res,2000,18 (4): 637-646
[66]Martino C F, Belchenko D, Ferguson V, et al. The effects of pulsed electromagnetic fields on the cellular activity of SaOS-2 cells. Bioelectromagnetics,2008,29 (2):125-132
[67]Icaro Cornaglia A, Casasco M, et al. Stimulation of osteoblast growth by an electromagnetic field in a model of bone-like construct. Eur J Histochem,2006,50(3):199-204
[68]Fitzsimmons R J, Ryaby J T, Magee F P, et al. IGF-Ⅱ receptor number is increased in TE-85 osteosarcoma cells by combined magnetic fields. J Bone Miner Res,1995,10 (5):812-819
[69]Bawin S M, Kaczmarek L K, Adey W R. Effects of modulated VHF fields on the central nervous system. Ann N Y Acad Sci,1975,247:74-81
[70]Wei L X, Goodman R, Gold S, et al. Changes in levels of c-myc and histone H2B following exposure of cells to low frequency sinusoidal signals:evidence for window effect. Bioelectromagnetics,1990,1:269-272
[71]Galvanovskis J, Sandblom J, Bergqvist B, et al. Cytoplasmic Ca2+oscillations in human leukemia T cells are reduced by 50 Hz magnetic fields. Bioelectromagnetics,1999,20:269-276
[72]Sontag W, Dertinger H. Response of cytosolic calcium, cyclic AMP, and cyclic GMP in Dimethylsulfoxide-differentiated HL-60 cells to modulated low frequency electric currents. Bioelectromagnetics,1998,19:452-458
[73]Doida Y, Miller M W, Brayman A A, et al. A test of the hypothesis that ELF magnetic fields affect calcium uptake in rat thymocytes in vitro. Biochem Bioph Res Co,1996,227:834-838
[74]Yost M G, Liburdy R P. Time-varying and static magnetic fields act in combination to alter calcium signal transduction in the lymphocyte. FEBS Lett,1992,296:117-122
[75]Ihrig I, Heese C, Glaser R. Alterations of intracellular calcium concentration in mice neuroblastoma cells by electrical field and UVA. Bioelectromagnetics,1997,18:595-597
[76]Boorman G A, Owen R D, Lotz W G, et al. Evaluation of in vitro effects of 50 and 60 Hz magnetic fields in regional EMF exposure facilities. Radiat Res,2000,153:648-657
[77]McCreary C R, Dixon S J, Fraher L J, et al. Real-time measurement of cytosolic free calcium concentration in Jurkat cells during ELF magnetic field exposure and evaluation of the role of cell cycle. Bioelectromagnetics,2006,27:354-364
[78]Loschinger M, Thumm S, Himmerleb H, et al. Induction of intracellular calcium oscillations in human skin fibroblast populations by sinusoidal extremely low-frequency magnetic fields (20 Hz, 8 mT) is dependent on the differentiation state of the single cell. Radiat Res,1999,151:195-200
[79]Spadaro J A. Mechanical and electrical interactions in bone remodeling. Bioelectromagnetics, 1997,18:193-202
[80]Zhang X, Liu X L, Sun J L, et al. Real-time observations of mechanical stimulus-induced enhancements of mechanical properties in osteoblast cells. Ultramicroscopy,2008,108:1338-1341
[2]Karsenty G. Role of Cbfal in osteoblast differentiation and function. Semin Cell Dev Biol,2000, 11:343-346
[3]熊志立,孟繁浩,李遇伯等.成骨细胞的骨形成调控机制.生命的化学,2004,Vol.24(1)44-46
[4]Tenforde T S. Biological interactions of extremely low-frequency electric and magnetic fields. Bioelectrochem Bioenerg,1991,25:1-17
[5]Pilla A A. Weak time-varying and static magnetic fields:from mechanisms to therapeutic applications. In:Stavroulakis P, eds. Biological effects of electromagnetic fields:mechanisms, modeling, biological effects, therapeutic effects, international standards, exposure criteria. Berlin: Springer,2003.352-394
[6]Liboff A R, Cherng S, Jenrow K A, et al. Calmodulin-dependent cyclic nucleotide phosphodiesterase activity is altered by 20 microT magnetostatic fields. Bioelectromagnetics, 2003,24:32-38
[7]Kindzelskii A L, Petty H R. Ion channel clustering enhances weak electric field detection by neutrophils:apparent roles of SKF96365-sensitive cation channels and myeloperoxidase trafficking in cellularresponses. Eur Biophys J,2005,35:1-26
[8]Otter M W, McLeod K J, Rubin C T. Effects of electromagnetic fields in experimental fracture repair. Clin Orthop Relat Res,1998,355:S90-104
[9]Liboff A R. Geomagnetic cyclotrone resonance in membrane transport. J Biol Phys,1985a,13: 99-102
[10]Pilla A A. Electrochemical information and energy transfer in vivo. In:Proceedings of seventh IECEC. Washington:American Chemical Society,1972.761-764
[11]McLeod K J, Rubin C T, Donahue H J. Electromagnetic fields in bone repair and adaption. Radio Sci,1995,30:233-244
[12]Schimmelpfeng J, Dertinger H. Action of a 50Hz magnetic field on proliferation of cells in culture. Bioelectromagnetics,1997,18:177-183
[13]Lednev V V. Possible mechanism for the influence of weak magnetic fields on biological systems. Bioelectromagnetics,1991,12:71-75
[14]Binhi V N. Interference ion quantum states within a protein explains weak magnetic field effects in biosystems. Electromagnetobiology,1997,16:203-214
[15]Gartzke J, Lange K. Cellular target of weak magnetic fields:ionic conduction along actin filaments ofmicrovilli. Am J Physiol Cell Physiol,2002,283:C1333-1346
[16]Bawin S M, Adey W R, Sabbot I M. Ionic factors in release of 45Ca2+ from chicken cerebral tissue
by eletromagnetic field. Proc Natl Acad Sci USA,1978,75 (12):6314-6318
[17]Adey W R. Cell membranes:the electromagnetic environment and cancer promotion. Neurochem Res,1988,13 (7):671-677
[18]Blackman C F. Influence of electromagnetic fields on the efflux of calcium ions from brain tissue in vitro:a three-model analysis consistent with the frequency response up to 510 Hz. Bioelectromagnetics,1988,9 (3):215-217
[19]陈树德,张红锋.低频电磁场对细胞生物效应的研究Chin J Phys Med,1998, Vol.20 (2): 78-80
[20]Lohmann C H, Schwartz Z, Liu Y, et al. Pulsed electromagnetic fields affect on phenotype and connexin 43 protein expression in MLO-Y4 osteocyte-like cells and ROS 17/2.8 osteoblast-like cells. J Orthop Res,2003,21(2):326-334
[21]李丽荣,罗二平,申广浩等.脉冲电磁场对体外培养成骨细胞的影响.中国医学物理学杂志,2005,Vol.22(1)：388-390
[22]Philips J L. Effects of electromagnetic field exposure on gene transcription. J Cell Biochem. 1993,51 (4):381-386
[23]Blank M, Goodman R. Do electromagnetic fields interact directly with DNA. Bioelectromagnetics,1997,18 (2):111-115
[24]Hartig M, Joos U, Wiesmann H P. Capaeitively coupled electric fields accelerate proliferation of osteoblast-like primary cells and increase bone extracellular matrix formation in vitro. Eur Biophys J,2000,29 (7):499-506
[25]Diniz P, Shomura K, Soejima K, et al. Effects of pulsed electromagnetic field (PEMF) stimulation on bone tissue like formation are dependent on the maturation stages of the osteoblasts. Bioelectromagnetics,2002,23 (5):398-405
[26]苏献双,张敏.电磁场促进骨形成的作用机制.口腔材料器械杂志,2005,Vol.14(2)：96-98
[27]Nagai M, Ots M. Pulsating electromagnetic fields stimulates mRNA expression of bone morphogenetic protein 2 and 4. J Dent Res,1994,73 (10):1601-1605
[28]Bodamyali T, Bhatt B, Hughes F J, et al. Pulsed electromagnetic fields simultaneously induce osteogenesis and upregulate transcription of bone morphogenetic proteins 2 and 4 in rat osteoblasts in vitro. Biochem Bioph Res Co,1998,250 (2):458-461
[29]Zhuang H, Wang W, Seldes R M, et al. Electrical stimulation induces the level of TGF-β1 mRNA in osteoblastic cells by a mechanism involving calcium/calmodulin pathway. Biochem Bioph Res Co,1997,237 (2):225-229
[30]Fitzsimmons R J, Strong D D, Mohan S, et al. Low-amplitude, low-frequency electric field-stimulated bone cell proliferation may in part be mediated by increased IGF-Ⅱ release. J Cell Physiol,1992,150(1):84-89
[31]Fitzsimmons R J, Ryaby J T, Mohan S, et al. Combined magnetic fields increase insuline-like growth factor Ⅱ in TE-85 human osteosarcoma bone cell cultures. Endocrinology,1995,136 (7): 3100-3106
[32]Lee J H, Mcleod K J. Morphologic responses of osteoblast-like cell in monolayer culture to ELF electromagnetic fields. Bioelectromagnetics,2000,21 (2):129-136
[33]Bersani F, Marinelli F, Ognibene A, et al. Intramembrane protein distribution in cell cultures is affected by 50 Hz pulsed magnetic fields. Bioelectromagnetics,1997,8 (7):463-469
[34]Chang K, Chang W H, Tsai M T, et al. Pulsed electromagnetic fields accelerate apoptotic rate in osteoclasts. Connect Tissue Res,2006,47(4):222-228
[35]Carson J J, Prato F S, Drost D J, et al. Time-varying magnetic fields increase cytosolic free Ca2+ in HL-60 cells. Am J Physiol,1990,259 (4 Pt 1):C687-C692
[36]Liburdy R P. Calcium signaling in lymphocytes and ELF fields Evidence for an electric field metric and a site of interaction involving the calcium ion channel. FEBS,1992,301(1):53-59
[37]Lindstrom E, Lindstrom P, Berglund A, et al. Intracellular calcium oscillations induced in a T-cell line by a weak 50 Hz magnetic field. J Cell Physiol,1993,156 (2):395-398
[38]Lyle D B, Fuchs T A, Casamento J P, et al. Intracellular calcium signaling by Jurkat T-lymphocytes exposed to a 60 Hz magnetic field. Bioelectromagnetics,1997,18 (6):439-445
[39]Sisken J E, DeRemer D. Power-frequency electromagnetic fields and the capacitative calcium entry system in SV40-transformed Swiss 3T3 cells. Radiat Res,2000,153 (5 Pt 2):699-705
[40]Shahidain R, Mullins R D, Sisken J E. Calcium spiking activity and baseline calcium levels in ROS 17/2.8 cells exposed to extremely low frequency electromagnetic fields (ELF EMF). Int J Radiat Biol,2001,77 (2):241-248
[41]Craviso G L, Poss J, Lanctot C, et al. Intracellular calcium activity in isolated bovine adrenal chromaffin cells in the presence and absence of 60 Hz magnetic fields. Bioelectromagnetics, 2002,23 (8):557-567
[42]Madec F, Billaudel B, Charlet de Sauvage R, et al. Effects of ELF and static magnetic fields on calcium oscillations in islets of Langerhans. Bioelectrochemistry,2003,60 (1-2):73-80
[43]Fitzsimmons R J, Ryaby J T, Magee F P, et al. Combined magnetic fields increased net calcium flux in bone cells. Calcif Tissue Int,1994,55:376-380
[44]Spadaro J A, Bergstrom W H. In vivo and In vitro effects of a pulsed electromagnetic field on net calcium flux in rat calvarial bone. Calcif Tissue Int,2002,70:496-502
[45]霍霞,徐锡金,陈耀文.激光扫描共聚焦显微镜荧光探针的选择和应用.激光生物学报,1999,Vol.8(2)：152-156
[46]Cain C D. Electromagnetic fields and signal transduction pathways. In:Brighton C T, Pollack S R, eds. Electromagnetic in Medicine and Biology. San Francisco:San Francisco Press,1991.61-65
[47]Luben R A. Effects of low-energy electromagnetic fields (pulsed and DC) on membrane signal transduction processes in biological systems. Health Physics,1991,61:15-28
[48]McLeod K J, Rubin C T. Observations from mechanically and electrically induced bone remodeling. In:Blank M, eds. Electricity and magnetism in biology and medicine. San Francisco: San Francisco Press,1993.98-700
[49]McLeod K J, Turner S, Rubin C T. Bone tissue adaption in response to high frequency mechanical perturbations. Ann Biomed Eng,1997,25 (S1):77
[50]Heermeier K, Spanner M, Trager J, et al. Effects of extremely low frequency electromagnetic field (EMF) on collagen type I mRNA expression and extracellular matrix synthesis of human osteoblastic cells. Bioelectromagnetics,1998,19:222-231
[51]Brighton C T, Wang W, Seldes R, et al. Signal transduction in electrically stimulated bone cells. J Bone Joint Surg Am,2001,83 (A10):1514-1523
[52]Diniz P, Soejima K, Ito G. Nitric oxide mediates the effects of pulsed electromagnetic field stimulation on the osteoblast proliferation and differentiation. Nitric Oxide,2002,7:18-23
[53]Goldbeter A, Dupont G, Berridge M L. Minimal model for signal-induced Ca2+ oscillations and for their frequency encoding through protein phosphorylation. Pro Natl Acad Sci USA,1990,87 (4):1461-1465
[54]Galvanovskis J, Sandblom J. Periodic forcing of intracellular calcium oscillators Theoretical studies of the effects of low frequency fields on the magnitude of oscillations. Bioelectrochemistry,1998,46:161-174
[55]Torres J J, Cornelisse L N, Harks E G, et al. Modeling action potential generation and propagation in NRK fibroblasts. Am J Physiol Cell Physiol,2004,287 (4):851-865
[56]Kusters J M, Dernison M M, van Meerwijk W P, et al. Stabilizing role of calcium storedependent plasma membrane calcium channels in action-potential firing and intracellular calcium oscillations. Biophy J,2005,89 (6):3741-3756
[57]Wong T K, Neumann E. Electric field mediated gene transfer. Biochem Bioph Res Co,1982,107 (2):584-587
[58]Lo M M S, Tsong T Y, Conrad M K, et al. Monoclonal antibody production by receptor-mediated electrically induced cell fusion. Nature,1984,310:792-794
[59]Mir L M, Orlowski S, Belehradek S. Electrochemotherapy potentiation of antitumour effect of bleomycin by local electric pulses. Eur J Cancer,1991,27 (1):68-72
[60]Adair R K. Biological effects on the cellular level of electric field pulses. Health Phys,1991,61 (1):395-399
[61]Fukuda E, Yasuda I. On the piezoelectric effect of bone. J Physiol Soc Jpn,1957,12:1158-1162
[62]Li J K, Lin J C, Liu H C, et al. Cytokine release from osteoblasts in response to different intensities of pulsed electromagnetic field stimulation. Electromagn Biol Med,2007,26 (3): 153-165
[63]Tsai M T, Chang W H, Chang K, et al. Pulsed electromagnetic fields affect osteoblast proliferation and differentiation in bone tissue engineering. Bioelectromagnetics,2007,28 (7): 519-528
[64]Selvamurugan N, Kwok S, Vasilov A, et al. Effects of BMP-2 and pulsed electromagnetic field (PEMF) on rat primary osteoblastic cell proliferation and gene expression. J Orthop Res,2007, 25(9):1213-1220
[65]Lohmann C H, Schwartz Z, Liu Y, et al. Pulsed electromagnetic field stimulation of MG63 osteoblast-like cells affects differentiation and local factor production. J Orthop Res,2000,18 (4): 637-646
[66]Martino C F, Belchenko D, Ferguson V, et al. The effects of pulsed electromagnetic fields on the cellular activity of SaOS-2 cells. Bioelectromagnetics,2008,29 (2):125-132
[67]Icaro Cornaglia A, Casasco M, et al. Stimulation of osteoblast growth by an electromagnetic field in a model of bone-like construct. Eur J Histochem,2006,50(3):199-204
[68]Fitzsimmons R J, Ryaby J T, Magee F P, et al. IGF-Ⅱ receptor number is increased in TE-85 osteosarcoma cells by combined magnetic fields. J Bone Miner Res,1995,10 (5):812-819
[69]Bawin S M, Kaczmarek L K, Adey W R. Effects of modulated VHF fields on the central nervous system. Ann N Y Acad Sci,1975,247:74-81
[70]Wei L X, Goodman R, Gold S, et al. Changes in levels of c-myc and histone H2B following exposure of cells to low frequency sinusoidal signals:evidence for window effect. Bioelectromagnetics,1990,1:269-272
[71]Galvanovskis J, Sandblom J, Bergqvist B, et al. Cytoplasmic Ca2+oscillations in human leukemia T cells are reduced by 50 Hz magnetic fields. Bioelectromagnetics,1999,20:269-276
[72]Sontag W, Dertinger H. Response of cytosolic calcium, cyclic AMP, and cyclic GMP in Dimethylsulfoxide-differentiated HL-60 cells to modulated low frequency electric currents. Bioelectromagnetics,1998,19:452-458
[73]Doida Y, Miller M W, Brayman A A, et al. A test of the hypothesis that ELF magnetic fields affect calcium uptake in rat thymocytes in vitro. Biochem Bioph Res Co,1996,227:834-838
[74]Yost M G, Liburdy R P. Time-varying and static magnetic fields act in combination to alter calcium signal transduction in the lymphocyte. FEBS Lett,1992,296:117-122
[75]Ihrig I, Heese C, Glaser R. Alterations of intracellular calcium concentration in mice neuroblastoma cells by electrical field and UVA. Bioelectromagnetics,1997,18:595-597
[76]Boorman G A, Owen R D, Lotz W G, et al. Evaluation of in vitro effects of 50 and 60 Hz magnetic fields in regional EMF exposure facilities. Radiat Res,2000,153:648-657
[77]McCreary C R, Dixon S J, Fraher L J, et al. Real-time measurement of cytosolic free calcium concentration in Jurkat cells during ELF magnetic field exposure and evaluation of the role of cell cycle. Bioelectromagnetics,2006,27:354-364
[78]Loschinger M, Thumm S, Himmerleb H, et al. Induction of intracellular calcium oscillations in human skin fibroblast populations by sinusoidal extremely low-frequency magnetic fields (20 Hz, 8 mT) is dependent on the differentiation state of the single cell. Radiat Res,1999,151:195-200
[79]Spadaro J A. Mechanical and electrical interactions in bone remodeling. Bioelectromagnetics, 1997,18:193-202
[80]Zhang X, Liu X L, Sun J L, et al. Real-time observations of mechanical stimulus-induced enhancements of mechanical properties in osteoblast cells. Ultramicroscopy,2008,108:1338-1341