No effects of intermittent 50�Hz EMF on cytoplasmic free calcium and on the mitochondrial membrane potential in human diploid fibroblasts

Abstract

The recently described increase in DNA strand breaks of cultured human diploid fibroblasts after intermittent exposure to extremely-low-frequency electromagnetic fields (ELF-EMF) of more than about 70 microT ELF-EMF is difficult to explain by a direct induction of covalent bond disruption. Therefore the hypothesis has been tested that ELF-EMF-induced DNA strand breaks might be mediated by cellular processes that cause alteration of the intracellular concentration of free calcium ([Ca2+]i) and/or the membrane potential (DeltaPsi(m)). [Ca2+]i was determined by the ratiometric fura-2 technique. Changes in DeltaPsi(m) were assessed by using the potential-dependent lipophilic cationic probe JC-1. Human fibroblasts were exposed to intermittent ELF-EMF (50 Hz, 1000 microT). Although exposure of fiboblasts to ELF-EMF resulted in a highly significant increase in DNA strand breaks as determined by the comet assay, no effect on JC-1 fluorescence emission or on [Ca2+]i has been observed when comparing exposed with sham-exposed cells. Therefore, it is suggested that ELF-EMF-induced DNA strand breaks are unlikely to be caused by intracellular changes that affect [Ca2+]i and/or DeltaPsi(m).

Effects of 3 Hz and 60 Hz Extremely Low Frequency Electromagnetic Fields on Anxiety-Like Behaviors, Memory Retention of Passive Avoidance and Electrophysiological Properties of Male Rats

“…Numerous investigations, from monitoring changes at molecular levels to the behavioral aspects, have been carried out in vitro and in vivo in order to illustrate different effects of ELF/EMF e.g., its impacts on cells, 1 hormones, [2][3][4][5][6] neurophysiological properties and sleep, 7,8 biochemical factors and metabolism, 9-11 pathology, 12,13 DNA damages and chromosome abnormalities, [14][15][16][17][18][19] reproduction and development, 20 and cancer. [21][22][23] On the other hand, the fact that central nervous system (CNS) as a very complicated electrochemical system may be influenced by electromagnetic fields attracts many researches interests.…”

Intracellular Ca2+Mobilization and Beta-hexosaminidase Release Are Not Influenced by 60 Hz-electromagnetic Fields (EMF) in RBL 2H3 Cells

“…Ionomycin is a well-known ionophore and increases intracellular Ca 2＋ concentration through Ca 2＋ -release activated Ca 2＋ (CRAC) channels [8]. Thapsigargin also increases intra- [16,17], to decrease it [18] and to have no effect on it [19,20]. Such different effects of EMF on intracellular Ca 2＋ concentration may be due to the cell types used and the experimental conditions.…”

Editorial expression of concern regarding: Pilger A et al. (2004) No effects of intermittent 50 Hz EMF on cytoplasmic free calcium and on the mitochondrial membrane potential in human diploid fibroblasts, Radiat Environ Biophys 43:203–207

“…In 2004, Radiation and Environmental Biophysics published a manuscript showing no effects of intermittent 50 Hz electromagnetic fields (EMF) on cytoplasmic free calcium and the mitochondrial membrane potential, while a significant effect of the EMF on DNA breakage as measured by comet assay was reported (Pilger et al 2004). This manuscript resulted from a collaboration between a group at the Medical University of Vienna headed by H.W.…”

“…A Letter to the Editor by A. Lerchl, which we received in May 2009, raised serious questions concerning the extremely small standard deviations of the data on DNA damage induced by EMF exposure, as shown in figure 1 of Pilger et al (2004). We asked two experts on biostatistics whether or not the suspicion expressed by A. Lerchl is justified.…”

“…On 1 February 2010, we were informed by the Medical University of Vienna that several publications of the group of H.W. Rüdiger, including the paper by Pilger et al (2004), under discussion here, are currently being investigated by the Austrian Agency for Scientific Integrity (http://www.oeawi.at).…”