Effects of a Time Varying Strong Magnetic Field on Release of Cytosolic Free Ca2+ from Intracellular Stores in Cultured Bovine Adrenal Chromaffin Cells
School of Pharmacy, The University of Tokushima, Tokusima, Tokushima, Japan Bioelectromagnetics
(Impact Factor: 1.71).
10/2002; 23(7):505-15. DOI: 10.1002/bem.10043
This study was made to explain the mechanisms for the effects of exposure to a time varying 1.51 T magnetic field on the intracellular Ca(2+) signaling pathway. The exposure inhibited an increase in intracellular Ca(2+) concentration ([Ca(2+)](i)) in bovine chromaffin cells induced by addition of bradykinin (BK) to a Ca(2+) free medium. The exposure did not change BK induced production of inositol 1,4,5-trisphosphate (IP(3)). [Ca(2+)](i) was markedly increased in IP(3) loaded cells, and this increase was inhibited by the magnetic field exposure. A similar increase in [Ca(2+)](i) by other drugs, which stimulated Ca(2+) release from intracellular Ca(2+) stores, was again inhibited by the same exposure. However, transmembrane Ca(2+) fluxes caused in the presence of thapsigargin were not inhibited by the magnetic field exposure in a Ca(2+) containing medium. Inhibition of the BK induced increase in [Ca(2+)](i) by the exposure for 30 min was mostly recovered 1 h after exposure ended. Our results reveal that the magnetic field exposure inhibits Ca(2+) release from intracellular Ca(2+) stores, but that BK bindings to BK receptors of the cell membrane and intracellular inositol IP(3) production are not influenced.
Available from: Guilherme Bertolino
- "Reports in the literature are still very heterogeneous in applicability, intensity, field types and exposure modes (Fanelli et al. 1999). Some studies have shown an effect of magnetic fields on cellular structures such as the membrane, cytoplasm, endoplasmic reticulum, and mitochondria (Pirozzoli et al. 2003; Tenforde 2003; Ikehara et al. 2002; Panagopoulos et al. 2002; Fanelli et al. 1999). From a functional perspective, the magnetic field influences the cell metabolism and rate of transcription of some genes, decreases spontaneous cell death in cultures and modifies the permeability of the plasma membrane (Fanelli et al. 1999). "
[Show abstract] [Hide abstract]
To evaluate the effects of continuous magnetic field stimulation after four days of global encephalic ischemia on motor behavior and brain morphology in gerbils.
Material and methods:
Sixty Mongolian gerbils were divided into five groups: Control (CG), sham (SG), ischemia (IG), ischemia north (INPG) and south (ISPG) pole. Experimental animals underwent bilateral occlusion of the carotid artery. In groups with magnetic stimulation, a 3200 gauss magnet was fixed to the skull. After brain perfusion, coronal sections of the striatum, motor cortex (M1) and CA1 area of the hippocampus (CA1) were cut and stained with hematoxylin and eosin.
In the open field test (OF) we observed an increase in crossing in the IG compared to the CG, INPG and ISPG (F = 20.19), and a reduction in the time spent on the Rota-rod test (RR) with the IG compared to CG, IPNG and ISPG (F = 17.59). Morphometric analysis revealed a reduction in the density of the neurons in the CA1, in the number of M1 and striatal neurons in the IG compared to the CG, INPG and ISPG.
Our results demonstrate a potential therapeutic application of static magnetic fields for the preservation of motor behavior and neurons in regions analyzed after global cerebral ischemia.
Available from: Mehmet Zulkuf Akdag
- "The study of cytosolic calcium concentration ([Ca 2+ ]c) may lead to further understanding the physical coupling between biological signals and ELF MF (Adey, 1993). Some studies reported that ELF-MF exposure can alter intracelluler calcium and cytosolic free calcium levels (Pessina et al., 2001; Ikehara et al., 2002; McCreary et al., 2006). Potential associations between bone mineral density (BMD) and dental status have been investigated (Bodic et al., 2005). "
[Show abstract] [Hide abstract]
ABSTRACT: Exposure to extremely low frequency magnetic fields (ELF-MF) emanating from the generation, distribution, and utilization of electricity is widespread. The major debate in recent years has focused on the possibility that exposure to ELF-MF may result in adverse health consequences. The present study was carried out to investigate the effects of ELF-MF on the mineral content in rat teeth. 27 male Sprague-Dawley rats were divided into three groups: two experimental (each, n=10), one control sham (n=7). After ELF-MF and sham exposure, some mineral levels (Ca, Mg, Zn, and P) were determined with Atomic Absorbtion Spectrophotometry (AAS). It was determined that Ca levels increased in the two experimental groups as compared to the sham group (p<.05). The levels of Ca, Mg, Zn, and P in second experimental group rats were also higher than sham group (p<.05). The results demonstrate that ELF-MF can have significant effects on teeth mineral content. Future observations and epidemiological studies of ELF-MF effects should be accompanied by laboratory experiments to evaluate oral and dental effects.
Available from: Anna Batistatou
- "Pulsed electromagnetic fields (PEMFs) are capable in altering the structure of the cell membranes and thus diversify the permeability of different ion channels and the potential of the cellular membranes. Both phenomena are important of cellular functions [Blackman et al., 1980; Walleczek and Liburdy, 1990; Ikehara et al., 2002], such as the production of chemical energy in the form of adenosine triphosphate (ATP) and the variance of intracellular free calcium levels, which is a second type universal intermediate ion [Carafoli, 2004]. They may also conserve the normal electrochemical gradient of cells, a necessary condition for ATP production, which may be lowered by ischemia or trauma. "
[Show abstract] [Hide abstract]
ABSTRACT: A variety of pulsed electromagnetic fields (PEMFs) have already been experimentally used, in an effort to promote wound healing. The aim of the present study was to investigate the effects of short duration PEMF on secondary healing of full thickness skin wounds in a rat model. Full thickness skin wounds, 2 by 2 cm, were surgically inflicted in two groups of male Wistar rats, 24 animals each. In the first group (experimental group - EG), the animals were placed and immobilized in a special constructed cage. Then the animals were exposed to a short duration PEMF for 20 min daily. In the second group (control group - CG), the animals were also placed and immobilized in the same cage for the same time, but not exposed to PEMF. On days 3, 6, 9, 12, 18, and 22, following the infliction of skin wounds, the size and healing progress of each wound were recorded and evaluated by means of planimetry and histological examination. According to our findings with the planimetry, there was a statistically significant acceleration of the healing rate for the first 9 days in EG, whereas a qualitative improvement of healing progress was identified by histological examination at all time points, compared to the control group.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.