Alterations in Calcium Ion Activity (original) (raw)
Related papers
Bioelectromagnetics, 1991
A technique based on release of calcium ions from in vitro preparations of avian brain tissues has been used by several investigators to demonstrate a biological effect of weak electric and magnetic fields. When the tissues have been exposed to ELF-modulated, VHF or UHF fields, enhanced release of calcium ions has resulted. In contrast, when the tissues have been exposed directly to an ELF field, outcomes have differed. Both inhibition and enhancement in release of calcium ions have been reported. We now find that either outcome-or a null result-is possible, depending on the temperature of tissue samples before and during exposure. Avian-brain tissues were exposed to 16-Hz sinusoidal electromagnetic fields at 14.1 Vrmc/m (in air) and 64 nT,,. During 20-min exposures, as tissue-sample temperature rose by 0.7 to 2.5 "C to a final temperature of 35, 36, or 37, but not of 38 or 39"C, an enhanced release of ions was observed. When the temperature was stable during exposure (i.e., constant within ?0.3"C) at a final value of 36 or 37, but not of 35 or 38"C, the quantity of ions released was reduced. And when descending by 0.7 to 1.5"C to any final temperature from 35 to 38"C, a null result occurred. These findings may reconcile the apparent disagreement in the direction of a field-induced response, and they may explain why experimental outcomes have been difficult to confirm in some laboratories. Of greater importance, the findings may also provide insight into the mechanism of the field-induced phenomenon.
Non-thermal effects of EMF upon the mammalian brain: the Lund experience
The Environmentalist, 2007
The environment in which biology exists has dramatically changed during the last decades. Life was formed during billions of years, exposed to, and shaped by the original physical forces such as gravitation, cosmic irradiation and the terrestrial magnetism. The existing organisms are created to function in harmony with these
Journal of Applied Biomedicine, 2008
This study aimed to examine the effects of short and long term exposures to 81 mG EMF intensity. It focused on the roles of ROS, Ca 2+ and calcium channel blocker (CCB) on the rat brain. Rats were exposed to 81 mG EMF intensity at the mobile phone base station for one and four weeks (2 hr/day, EMF exposed group). Another group of rats was pretreated with CCB (amlodipine 20 mg/kg) for four weeks and similarly exposed to EMF (EMF + amlodipine group). Sham exposed and amlodipine control groups were used. At the end of the study, Ca 2+ as well as pro-inflammatory and oxidative stress markers were measured. Immunohistochemical staining for Bax in brain samples was carried out. Short term exposure evoked a cellular adaptation response. This was evident by a transient increase in brain levels of Ca 2+ , glutathione (GSH) and serum tumor necrosis factor alpha (TNFα). Long term exposure to EMF was lethal; progressive oxidative damage, and a prolonged increase in the Ca 2+ level accompanied by a marked pro-inflammatory reaction (TNFα and CRP) were demonstrated. These alterations were ameliorated by pre-and con-comitant treatment with amlodipine. Furthermore, it restored the EMF induced apoptosis in brain to near normal. In conclusion, EMF is a stressor agent that induces an imbalance between ROS generation and antioxidant defense response. Calcium ions may play a pivotal role in enhancing oxidative stress, pro-inflammatory reactions and apoptosis associated with EMF exposure. Therefore calcium channel blockade seems to play a role in brain protection.
DergiPark (Istanbul University), 2012
The aim of the study was to investigate the effects of electromagnetic fields (EMF) to whole protein, neuron specific enolase (NSE), myelin basic protein (MBP) profiles and nitric oxide levels in rat brains. In addition, serum NSE was also determined. For this aim, 33 rats with 2-days-old age were divided into three groups. The rats in control group were kept in the normal conditions with no exposure of EMF. Group 2 and 3 were exposed to 900 and 1800MHz EMF respectively for 2 h/day for 90 days at the same time and everyday in the piecage restrainer. At the end of the exposure period, the brains of rats were excluded and splitted up to two parts (right and left), horizontally. The brain parts of same groups were mixed, homogenized and sonicated. The protein concentrations were equalized to 40 mg/ml with spectrophotometer. The protein profiles were determined for sizes and densities of bands with SDS-PAGE. NSE and MBP profiles were detected with western blot technique. Nitric oxide levels were determined by using ELISA test kit. The sizes of protein bands were detected as being same but the densities were found as variable into the groups for all parameters. The protein band, MBP and NSE densities of brains of rats were defined as increased in group 2, but decreased in group 3 when compared with control group. Also, there was no difference seen in right and left parts of brains in all groups. NSE in serum was determined to be higher in group 3 than the group 2 and control. Nitric oxide levels in the right and left brain parts were 224.09±20.32 µM/mL and 207.43±24.19 µM/mL in control group, 253.8±33.58 µM/mL and 336.9±24.47 µM/mL in group 2, 237.87±36.30 µM/mL and 281.53±36.75 µM/mL in group 3, respectively. The difference of nitric oxide levels among the groups was found as not significant (P>0.05). The results of this study may lighten the future and advance studies about the risks of the cellular and digital communication handsets against brain used by the general public.
Effect of ambient levels of power-line-frequency electric fields on a developing vertebrate
Bioelectromagnetics, 1988
Fertilized eggs of Gallus domesticus were exposed continuously during their 21-day incubation period to either 50-or 60-Hz sinusoidal electric fields at an average intensity of 10 Vrmslm. The exposure apparatus was housed in an environmental room maintained at 37°C and 55-60% relative humidity (RH). Within 1.5 days after hatching, the chickens were removed from the apparatus and tested. The test consisted of examining the effect of 50-or 60-Hz electromagnetic fields at 15.9 Vrmsim and 73 nTrms (in a local geomagnetic field of 38 pT, 85"N) on efflux of calcium ions from the chicken brain. For eggs exposed to 60-Hz electric fields during incubation, the chicken brains demonstrated a significant response to 50-Hz fields but not to 60-Hz fields, in agreement with the results from commercially incubated eggs [Blackman et al., 1985al. In contrast, the brains from chicks exposed during incubation to 50-Hz fields were not affected by either 50or 60-Hz fields. These results demonstrate that exposure of a developing organism to ambient power-linefrequency electric fields at levels typically found inside buildings can alter the response of brain tissue to field-induced calcium-ion efflux. The physiological significance of this finding has yet to be established.
2020
Studies on the potential effect of EMF exposure on permeability of the blood-brain barrier (BBB) in humans are virtually absent. This study was conducted to study the effect of EMF exposure on pericytes in brain tissues and its effect on oxidative stress level in the blood through total protein and malondialdehyde (MDA). About 16 male rats ( Wistar ) were used and divided into two groups which are negative control and treatment group. In negative control group, the animals were placed in a solenoid without any EMF exposure for 3 hours daily for 5 days. In the treatment group, the animals were placed in a solenoid with 0.3 mT EMF exposure for the same time duration. On day 3 and day 5, animals were sacrificed and the brain was removed for histological examination while on day 1, day 3 and day 5, the blood was collected for biochemistry analysis. Histological observation showed the presence of morphological changes in the brain tissues of rats that exposed to EMF. Statistical analysis...
Non thermal effects of radiofrequency electromagnetic field exposure on neural cells
EPJ Web of Conferences
The non-thermal mechanisms, underlying the damage induced on human cells by radiofrequency electromagnetic fields (RF-EMFs), are still unclear and only few studies reported about the effect of RFEMFs on self-renewal of neural progenitor cells. In this research, we investigated the influence of low-intensity RF-EMFs on Olfactory Ensheathing Cell (OEC) cultures, typical glia cells showing characteristics of stem cells. Cell cultures were exposed, in far-field condition, at 900 MHz continuous and amplitude modulated EMFs for 10, 15 and 20 min at 37°C. The expression of OEC marker (S-100), stem cell marker (Nestin), cytoskeletal proteins (GFAP and Vimentin), apoptotic pathway activation by Caspase-3 cleavage and cell viability, were evaluated. Surprisingly 20 min of exposure to continuous or amplitude modulated 900 MHz EMF induced a different and significant decrease in cell viability, some dynamic changes in the expression of the analysed markers and in the activation of the apoptotic ...