Morris Cassandra E, Skalak Thomas C
Department of Biomedical Engineering, University of Virginia Health Sciences Center, Health System, Charlottesville, VA 22908, USA.
Am J Physiol Heart Circ Physiol. 2008 Jan;294(1):H50-7. doi: 10.1152/ajpheart.00529.2007. Epub 2007 Nov 2.
External application of static magnetic fields (SMF), used specifically for the treatment of inflammatory conditions such as soft tissue injuries, has recently become popular as a complementary and/or alternative therapy with minimal investigation into efficacy or mechanism. Localized inflammation was induced via injection of inflammatory agents lambda-carrageenan (CA) or histamine into rat hindpaws, alone or in conjunction with pharmacological agents, resulting in a spatially and temporally defined inflammatory reaction. Application of a 10- or 70-mT, but not a 400-mT, SMF for 15 or 30 min immediately following histamine-induced edema resulted in a significant, 20-50% reduction in edema formation. In addition, a 2-h, 70-mT field application to CA-induced edema also resulted in significant (33-37%) edema reduction. Field application before injection or at the time of maximal edema did not influence edema formation or resolution, respectively. Together, these results suggest the existence of a therapeutic threshold of SMF strength (below 400 mT) and a temporal dependence of efficacy. Administration of pharmacological agents directed at nitric oxide signaling and L-type Ca(2+) channel dynamics in conjunction with SMF treatment and histamine-induced edema revealed that the potential mechanism of SMF action may be via modulation of vascular tone through effects on L-type Ca(2+) channels in vascular smooth muscle cells.
静磁场（SMF）的外部应用专门用于治疗诸如软组织损伤等炎症性疾病，最近已成为一种补充和/或替代疗法，但对其疗效或作用机制的研究极少。通过向大鼠后爪注射炎症介质λ-角叉菜胶（CA）或组胺单独或与药理剂联合诱导局部炎症，从而产生空间和时间上明确的炎症反应。在组胺诱导水肿后立即施加10或70 mT（而非400 mT）的静磁场15或30分钟，可使水肿形成显著减少20 - 50%。此外，对CA诱导的水肿施加2小时、70 mT的磁场也可使水肿显著减少（33 - 37%）。在注射前或水肿最大时施加磁场分别不影响水肿的形成或消退。总之，这些结果表明存在静磁场强度的治疗阈值（低于400 mT）以及疗效的时间依赖性。与静磁场治疗和组胺诱导的水肿联合使用针对一氧化氮信号传导和L型钙通道动力学的药理剂表明，静磁场作用的潜在机制可能是通过影响血管平滑肌细胞中的L型钙通道来调节血管张力。
