Low frequency MFs increased inositol 1,4,5‐trisphosphate levels in the Jurkat cell line

We have earlier reported that when a weak 50 Hz MF (magnetic field) was applied, the leukemic T-cell line Jurkat responded with intracellular calcium oscillations [Lindström, et al., J. Cell Physiol., 156 (1993) 395-398]. The result suggested that the MF interfered with the signal transduction, although neither target molecules nor molecular mechanisms are at present known. In this study we found that application of a MF to Jurkat cells resulted in significant increase of inositol 1,4,5-trisphosphate (IP3) levels. Chelation of intracellular calcium ions by BAPTA/AM, did not block the increase of IP3 induced by MF. This result implied that MF-induced Ca2+ oscillations were not due to direct stimulation of the Ca(2+)-dependent phospholipase C-gamma 1 (PLC-gamma 1).