EFFECT OF ELF PULSED ELECTROMAGNETIC-FIELDS ON PROTEIN-KINASE-C ACTIVATION PROCESS IN HL-60 LEUKEMIA-CELLS

The activation of protein kinase C in HL-60 cells has been used as a model to investigate the molecular effects of the interaction of ELF pulsed electromagnetic fields (PEMFs) with the living systems. The shape of the pulsed magnetic field used in our experiments was a positive triangle (50 Hz, 8 mT peak). Protein kinase C is activated by association with plasma membranes; the membrane-associated enzyme binds phorbol esters. In the present study the process of protein kinase C activation was studied by measuring the binding of [H-3]-phorbol-12, 13-dibutyrate. The extent of labelled PDBu binding to HL-60 cells was increased by exposing the cells to the ELF electromagnetic field. Scatchard analysis of PDBu binding data showed an increased number of binding sites for the PDBu in the cells exposed to the electromagnetic field for 10, 15 or 20 min. Addition of EGTA to the culture medium resulted in a smaller stimulation of protein kinase C activation in the cells exposed to PEMF.