THE EFFECT OF IRON IONS AND WEAK STATIC OR LOW FREQUENCY (50 HZ) MAGNETIC FIELDS ON LYMPHOCYTES: FREE RADICAL PROCESSES

摘要

The aim of the work is to present our observations and suggestions that changes in the oxidative processes and number of free oxygen radicals in cells affected by the iron ions and weak static or power frequency magnetic fields (MF) could be qualitatively explained by the radical pair mechanism. The experiments were performed on rat lymphocytes. Exposures to static or 50 Hz MF were performed inside a pair of Helmholtz coils. Iron ions (FeCl_2) were used as a stimulator of the oxidation processes. Oxygen radicals were measured by fiuorimetry using a DCF-DA fluorescent probe. The alkaline comet assay was chosen for the assessment of DNA damage. During pre-incubation, a portion of the cell samples were supplemented with melatonin (0.5 or 1.0 mM) or trolox (0.1 mM). For studying cell death and morphological changes in the nucleus, we used dye exclusion method with DNA-fluorochromes: ethidium bromide and acridine orange. A decrease of fluorescence in relation to non-exposed samples occurred in the lymphocytes exposed to 40 μT MF (only when axis of Helmholtz coils was directed along Earth's static MF). In the lymphocytes exposed to 50 Hz MF at 7 mT flux density, there was an increase of fluorescence in relation to non-exposed samples, the effect opposite to that observed in 40 μT. A significant increase in the number of cells with damaged DNA was found after simultaneous exposure of lymphocytes to FeCl_2 and (7 mT) 50 Hz MF, compared to the control samples or those incubated with FeCl_2 alone. However, when the cells were treated with melatonin or trolox and then exposed to iron ions and 50 Hz MF, the number of damaged cells was significantly reduced. The results also indicate that melatonin was less effective than vitamin E (trolox) under the experimental conditions used in our experiments. When lymphocytes were exposed to 7 mT SMF and simultaneously treated with FeCl_2, there was also a significant increase in the percentage of apoptotic and necrotic cells accompanied by significant alterations in cell viability. Our findings seem to confirm the hypothesis that low level static or power MF affect oxidative processes in the cells and these changes are compatible with the model of electromagnetic radiation effect on radical pairs.