the Science of the -Ibt.alEllvhlment An,*--*-- lm.I*m.-L~-.*hMI The Science of the Total Environment 180 (1996) 19-33 The influence of SO-HZ magnetic fields on cytoplasmic Ca*+ oscillations in human leukemia T-cells Juris Galvanovskis*“, John Sandblom”, Bjiim Bergqvistb, Sheila Galtb, Yngve Hamneriusb aDepariment of Medical Biophysics, Uniwrsity of Gothenbq, Gothenburg Sweden hDepanment of Microwave Technology, Chalmers Uniwrsity of Technology, Gothenbtug Sweden Abstract We havestudiedthe effects of 50-Hz NO-PT rmsmagneticfieldson intracellular Ca2+ concentration in the Jurkat T lymphocyte variant E6.1 using fluorescent probes Indo-l and Fura-2. We found, however, that the pattern of intracellular Ca*+ fluctuations also depended on the agent used for cell attachment, in our case the polypeptide poiy-r.-lysine. In order to isolatepossible effects of magneticfield exposure from those of poly-L-lysine, the action of polypeptideon cytosolic Ca*+ wasstudiedas well. It wasfound that a 10m7% concentration of polypeptide triggered prolonged Ca2+ spiking. Higher (10-4%) concentrations induced rapid increases in intracellular Ca*+ followed by high, unstable Ca *+ levels The response of these cells to the monoclonal antibody anti-CD3 was also inhomoge- . neous, similar to one caused by poly+lysine. The effect of magnetic field exposure was studied on cells initially exhibiting (1) non-oscillating, low Ca*+ concentration and (2) prolonged Ca*’ concentration oscillations. In case (1) the result wasnegative. In case (2), statistically significant changes were found: the oscillation amplitudewasreduced on averageby 30%, and the frequency composition wasshifted towards higher frequencies. Keywords: Magnetic field; Intracellular Ca *+; Poly-L-lysine; T lymphocyte 1. Introduction Over the last two decades it has become in- creasingly evident that an external stimulation of many types of cells leads to the oscillatory changes of intracellular Ca*’ that are thought to be in- volved in the signal transduction from the cellular membrane to certain targets inside a cell [1,21. *Corresponding author In the case of lymphocytes it has been shown that an oscillatory response can be evoked by external stimulation with anti-surface immuno- globulins or trinitrophenyl-Ficoll [3] and with mi- togenic lectins [4]. Payet et al. [5] have reported the existence of spontaneous Ca*+ concentration oscillations in two variants (E6.1 and 77 6.8) of human T (Jurkat) cells. There have also been observations that low frequency weak magnetic fields can be an exter- nal factor capable of inducing intracellular Ca*+ 0048-9697/96/$15.00 0 1996 Elsexier Science BV. All rights reserved. SSDI 0048-9697(95)04916-O