EFFECTS OF ELECTROMAGNETIC STIMULI ON BONE AND BONE-CELLS INVITRO - INHIBITION OF RESPONSES TO PARATHYROID-HORMONE BY LOW-ENERGY LOW-FREQUENCY FIELDS
EFFECTS OF ELECTROMAGNETIC STIMULI ON BONE AND BONE-CELLS INVITRO - INHIBITION OF RESPONSES TO PARATHYROID-HORMONE BY LOW-ENERGY LOW-FREQUENCY FIELDS
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DOI：
10.1073/pnas.79.13.4180
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发表时间：
1982-01-01
期刊：
影响因子：
--
通讯作者：
ADEY, WR
中科院分区：
文献类型：
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作者：
LUBEN, RA;CAIN, CD;ADEY, WR
频率为10-90 Hz的低能量脉冲电磁场显著促进人类慢性骨折不愈合的愈合，这些场在比正常细胞跨膜去极化所需的组织电流水平低几个数量级的组织电流水平下有效。研究了2种临床常用的脉冲电磁场对成骨样小鼠骨细胞系MMB-1培养物的影响。这两个领域显着减少细胞产生的cAMP的甲状旁腺激素和破骨细胞活化因子。无论是基础还是氟激活水平的腺苷酸环化酶被改变膜从细胞培养在外地，然而，同样的膜制剂表现出显着抑制甲状旁腺激素的反应。磁场阻断了激素对MMB-1细胞胶原合成的抑制作用。1，25-二羟维生素D3对胶原蛋白合成的抑制作用没有影响，据信主要通过核机制而不是膜依赖性机制发挥作用。两个场的效应之间没有显著差异，一个场产生连续脉冲串（72 Hz），另一个场产生较短脉冲的复发性爆发（15 Hz）。这些场效应主要在成骨细胞的质膜上介导，通过干扰受体-受体相互作用或通过阻断膜中的受体-环化酶偶联。这些反应发生在诱导的细胞外电场≤1 mV/cm，即使跨膜电位梯度通常为105 V/cm。
Low-energy electromagnetic fields pulsed at frequencies of 10-90 Hz significantly increase healing of chronic fracture nonunions in man. These fields are effective at tissue current levels several orders of magnitude lower than those required for transmembrane depolarization of normal cells. The effects of 2 clinically used pulsed electromagnetic fields on cultures of the osteoblast-like mouse bone cell line MMB-1 were examined. Both fields significantly reduced cellular production of cAMP in response to parathyroid hormone and osteoclast activating factor. Neither basal nor fluoride-activated levels of adenylate cyclase were altered in membranes from cells cultured in the field; however, the same membrane preparations exhibited markedly inhibited responses to parathyroid hormone. The fields blocked the inhibitor effects of the hormone on collagen synthesis by MMB-1 cells. There was no effect on the inhibition of collagen synthesis by 1,25-dihydroxyvitamin D3, which is believed to act primarily by a nuclear, rather than by a membrane-dependent, mechanism. No significant differences were noted between effects of the 2 fields, one generating continuous pulse trains (72 Hz) and the other generating recurrent bursts (15 Hz) of shorter pulses. These field effects are mediated primarily at the plasma membrane of osteoblasts, either by interference with hormone-receptor interactions or by blocking of receptor-cyclase coupling in the membrane. These responses occurred with induced extracellular fields of .ltoreq. 1 mV/cm, even though transmembrane potential gradients are typically 105 V/cm.