Carson J J, Prato F S, Drost D J, Diesbourg L D, Dixon S J
Lawson Research Institute, St. Joseph's Health Centre, London, Ontario, Canada.
Am J Physiol. 1990 Oct;259(4 Pt 1):C687-92. doi: 10.1152/ajpcell.1990.259.4.C687.
Electromagnetic fields have been reported to cause a variety of biological effects. It has been hypothesized that many of these phenomena are mediated by a primary effect on the concentration of cytosolic free calcium ([Ca2+]i). We investigated the effects of exposure to electromagnetic fields on [Ca2+]i in HL-60 cells using the Ca2(+)-sensitive fluorescent indicator indo-1. Indo-1-loaded cell samples were exposed to a radiofrequency electromagnetic field, a static magnetic field, and a time-varying magnetic field, which were generated by a magnetic resonance imaging (MRI) unit. We found that a 23-min exposure to all three fields, in combination, induced a significant increase in [Ca2+]i of 31 +/- 8 (SE) nM (P less than 0.01, n = 13) from a basal level of 121 +/- 8 nM. Also, cells exposed to only the time-varying magnetic field had a mean [Ca2+]i that was 34 +/- 10 nM (P less than 0.01, n = 11) higher than parallel control samples. Separate exposure to the radio-frequency (6.25 MHz) or static field (0.15 T) had no detectable effects. These results demonstrate that time-varying magnetic fields alter [Ca2+]i and suggest that at least some of the reported biological effects of time-varying magnetic fields may arise from elevation of [Ca2+]i.
据报道，电磁场会引发多种生物效应。据推测，其中许多现象是由对胞质游离钙浓度（[Ca2+]i）的原发性影响介导的。我们使用Ca2+敏感荧光指示剂indo-1研究了暴露于电磁场对HL-60细胞中[Ca2+]i的影响。将加载indo-1的细胞样本暴露于由磁共振成像（MRI）设备产生的射频电磁场、静磁场和时变磁场中。我们发现，将所有三种场联合暴露23分钟，会使[Ca2+]i从121±8 nM的基础水平显著增加31±8（SE）nM（P<0.01，n = 13）。此外，仅暴露于时变磁场的细胞，其平均[Ca2+]i比平行对照样本高34±10 nM（P<0.01，n = 11）。单独暴露于射频（6.25 MHz）或静磁场（0.15 T）没有可检测到的影响。这些结果表明，时变磁场会改变[Ca2+]i，并表明时变磁场报道的至少一些生物效应可能源于[Ca2+]i的升高。
