Cytoplasmic Ca2+ oscillations in human leukemia T-cells are reduced by 50 Hz magnetic fields

The effect of 50 Hz magnetic fields on the cytosolic calcium oscillator in Jurkat E6.1 cells was investigated for field strengths within the range fro m 0 to 0.40 mT root mean square. The intracellular Ca2+ concentration data were collected for single Jurkat cells that exhibited a sustained spiking f or at least 1 h while repeatedly exposing them to an alternating magnetic f ield in 10-min intervals interposed with nonexposure intervals of the same length. The obtained data were analysed by computing spectral densities of the Ca2+ oscillating patterns for each of these 10-min intervals. For every single-cell experiment the spectra of all exposure as well as nonexposure periods were then averaged separately. A comparison between the resulting a verages showed that the total spectral power of the cytosolic Ca2+ oscillat or was reduced by exposure of the cells to an alternating magnetic field an d that the effect increased in an explicit dose-response manner. The same r elationship was observed within the 0-10 mHz (10 x 10(-3) Hz) subinterval o f the Ca2+ oscillation spectrum. For subintervals at higher frequencies, th e change caused by the exposure to the magnetic field was not significant. (C) 1999 Wiley-Liss, Inc.