Low frequency amplitude modulated microwave fields change calcium efflux rates from synaptosomes

Lin-Liu, S.; Adey, W. R.

doi:10.1002/bem.2250030303

Cited by 95 publications

(37 citation statements)

References 19 publications

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“…The mechanisms by which RF radiation interacts with metals or ions in cells and tissues remain unknown. Although it has been reported that RF radiation changed calcium efflux rates in culture cells [7,19], whether RF radiation affected calcium efflux or not was still contradictory [6]. The present results showed that exposure to RF radiation at 40 kHz induced hepatic injury in LEC rats, although adverse effects were not found in normal control rats (WKAH rats) after exposure to RF radiation.…”

Section: Discussioncontrasting

confidence: 60%

Radiofrequency Radiation at 40kHz Induces Hepatic Injury in Long-Evans Cinnamon (LEC) Rats, an Animal Model for Human Wilson Disease

Sakai

Horiguchi

Endoh

et al. 2011

The Journal of Veterinary Medical Science

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ABSTRACT. In the present study, we examined effects of radiofrequency (RF) radiation at 40 kHz on hepatic injury in Long-Evans Cinnamon (LEC) rats, an animal model for human Wilson disease, which is a heritable disease of copper metabolism in the liver. The activities of ALT and AST in serum of LEC rats exposed to RF radiation for 2 weeks were approximately 3.8-fold and 2-fold higher than those in serum of sham-exposed rats, respectively. Although there were no significant differences in hepatic copper contents between LEC rats exposed to RF radiation for 2 weeks and sham-exposed rats, copper contents in the kidney and serum of exposed LEC rats were approximately 4.2-fold and 12.9-fold higher than those in sham-exposed rats, respectively. Relative O 2 --scavenging activities in the S-100 fraction of the liver of LEC rats exposed to RF radiation for 2 weeks were 1.6-fold higher than those in sham-exposed rats. No significant differences were observed in activities of AST and ALT in serum and relative O 2 --scavenging activity in the S-100 fraction of the liver of normal control WKAH rats that were sham-exposed and exposed to RF radiation. No significant differences were observed in copper contents in the liver, kidney and serum of WKAH rats that were sham-exposed and exposed to RF radiation for 2 weeks. The results show that RF radiation at 40 kHz induced hepatic injury in LEC rats.

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Section: Discussioncontrasting

confidence: 60%

Radiofrequency Radiation at 40kHz Induces Hepatic Injury in Long-Evans Cinnamon (LEC) Rats, an Animal Model for Human Wilson Disease

Sakai

Horiguchi

Endoh

et al. 2011

The Journal of Veterinary Medical Science

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“…The (14) and in its synaptosomal fractions (15) and are similarly ineffective in modulating cell-mediated cytotoxicity of T lymphocytes (16), phenomena that are -strongly responsive to radio and microwave fields amplitude modulated at frequencies <100 Hz. We have confirmed that these fields produced an electrical gradient of ==I.O mV/cm around a 1-cm ioop in the spatially homogeneous portion ofthe field between the coils and that the expected peak extracellular current density in homogeneous conducting electrolytes would be =zzl.0 pA/cm2 ('13 (6).…”

Section: Methodsmentioning

confidence: 99%

Effects of electromagnetic stimuli on bone and bone cells in vitro: Inhibition of responses to parathyroid hormone by low-energy low-frequency fields

Luben

Cain

Chen

et al. 1982

Proc. Natl. Acad. Sci. U.S.A.

267

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Low-energy electromagnetic fields pulsed at frequencies of 10-90 Hz significantly increase healing ofchronic fracture nonunions in man. These fields are effective at tissue current levels several orders of magnitude lower than those required for transmembrane depolarization ofnormal cells. We have examined the effects of two clinically used pulsed electromagnetic fields on cultures of the osteoblast-like mouse bone cell line MMB-1. Both fields significantly reduced cellular production of cAMP in response to parathyroid hormone and osteoclast activating factor. Neither basal nor fluoride-activated levels of adenylate cyclase were altered in membranes from cells cultured in the fields; however, the same membrane -preparations exhibited markedly inhibited responses to parathyroid hormone. The fields blocked the inhibitory effects of the hormone on collagen synthesis by MMB-1 cells. However, there was no effect on the inhibition of collagen synthesis by 1,25-dihydroxyvitamin D3, which is believed to act primarily by a nuclear, rather than by a membrane-dependent, mechanism. No significant differences were noted between effects of the two fields, one generating continuous pulse trains (72 Hz) and the other generating recurrent bursts (15 Hz) of shorter pulses. We hypothesize that these field effects are mediated primarily at the plasma membrane of osteoblasts, either by interference with hormone-receptor interactions or by blocking of receptor-cyclase coupling in the membrane. These responses occurred with induced extracellular fields of 1 mV/cm or less, even though transmembrane potential gradients are typically 105 V/cm.Clinical studies (1-5) have demonstrated the usefulness ofelectromagnetic fields in stimulatinghealing ofchronically ununited fractures in humans. Devices generating such fields have been approved for clinical use. However, the mechanisms of action of these fields are not clear. Oscillating electromagnetic fields proven effective in clinical use generate electrochemical gradients in the tissue fluid surrounding cells (6), but these gradients are considerably weaker than the levels required to depolarize cell membranes. Typically, the devices in question impose -20-G pulsed magnetic fields, which induce current densities of -1 uA/cm2 and associated electric gradients of 1-10 mV/cm in extracellular fluids (2). Because of the high resistance ofcell membranes, any transmembrane electrical components ofimposed fields would be lower than the extracellular gradients by two to three orders of magnitude (6) and thus as much as six orders of magnitude less than the typical excitatory threshold currents of 1 mA/cm2 observed for axonal depolarization (7).It would therefore appear that the effectiveness ofsuch weak stimuli in generating cellular processes must depend on a series of amplification mechanisms, either before or during the transmembrane coupling of the initial stimulus (8). Likely loci for amplification and extension of weak electrochemical triggering events at the cell membrane may involve ...

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“…One hypothesis is that a field could induce changes in the cellular membranes, influencing either directly or indirectly receptor-binding properties of the ligands such as Ca 2+, neurotransmitters, hormones, etc. [11,12]. Another possibility is that the magnetic fields could act through cyclotron effects [13].…”

Section: Introductionmentioning

confidence: 99%

Dual effects of microwaves on single Ca²⁺‐activated K⁺ channels in cultured kidney cells Vero

et al. 1995

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Using the patch voltage-clamp method, possible effects of millimetre microwaves (42.25 GHz) on single CaZ+-activated K + channels in cultured kidney cells (Vero) were investigated. It was found that exposure to the field of non-thermal power (about 100 btW/cm 2) for 20-30 min greatly modifies both the Hill coefficient and an apparent affinity of the channels for Ca2~. The data suggest that the field alters both cooperativity and binding characteristics of the channel activation by internal Ca 2+. The effects depend on initial sensitivity of the channels to Ca 2+ and the Ca 2+ concentration applied.

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Low frequency amplitude modulated microwave fields change calcium efflux rates from synaptosomes

Cited by 95 publications

References 19 publications

Radiofrequency Radiation at 40kHz Induces Hepatic Injury in Long-Evans Cinnamon (LEC) Rats, an Animal Model for Human Wilson Disease

Radiofrequency Radiation at 40kHz Induces Hepatic Injury in Long-Evans Cinnamon (LEC) Rats, an Animal Model for Human Wilson Disease

Effects of electromagnetic stimuli on bone and bone cells in vitro: Inhibition of responses to parathyroid hormone by low-energy low-frequency fields

Dual effects of microwaves on single Ca²⁺‐activated K⁺ channels in cultured kidney cells Vero

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Low frequency amplitude modulated microwave fields change calcium efflux rates from synaptosomes

Cited by 95 publications

References 19 publications

Radiofrequency Radiation at 40kHz Induces Hepatic Injury in Long-Evans Cinnamon (LEC) Rats, an Animal Model for Human Wilson Disease

Radiofrequency Radiation at 40kHz Induces Hepatic Injury in Long-Evans Cinnamon (LEC) Rats, an Animal Model for Human Wilson Disease

Effects of electromagnetic stimuli on bone and bone cells in vitro: Inhibition of responses to parathyroid hormone by low-energy low-frequency fields

Dual effects of microwaves on single Ca2+‐activated K+ channels in cultured kidney cells Vero

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Dual effects of microwaves on single Ca²⁺‐activated K⁺ channels in cultured kidney cells Vero