EFFECT OF EXTREMELY-LOW-FREQUENCY (ELF) MAGNETIC-FIELD EXPOSURE ON MORPHOLOGICAL AND BIOPHYSICAL PROPERTIES OF HUMAN LYMPHOID-CELL LINE (RAJI)

Human B lymphoid cells (Raji) were exposed for 72 h to a 50 Hz sinusoi dal magnetic field at a density of 2 milliTesla (rms). The results of exposure showed a decrease in membrane fluidity as detected by Laurdan emission spectroscopy and DPH fluorescence polarization. Field exposu re also resulted in a reorganization of cytoskeletal components. Scann ing electron microscopy (SEM) revealed a loss of microvilli in the exp osed cells. This change in plasma membrane morphology was accompanied by a different actin distribution, as detected by phalloidin fluoresce nce. We also present evidence that EMF exposure of Raji cells can inte rfere with protein phosphorylation. Our observations confirm the hypot hesis that electric and magnetic fields may modify the plasma membrane structure and interfere with the initiation of the signal cascade pat hways. (C) 1997 Published by Elsevier Science B.V.