Cheun BS, Yi SH, Baik KY, Lim JK, Yoo JS, Shin HW, Soh KS · 2007
Researchers studied biophoton emission from Madin-Darby canine kidney (MDCK) cells treated with hydrogen peroxide, with and without exposure to a 60 Hz AC magnetic field. Hydrogen peroxide increased biophoton emission from the cells, and the increase was dependent on the amount of hydrogen peroxide applied. When the 60 Hz AC magnetic field was applied, the decay of chemiluminescence intensity took a different path compared to cells not exposed to the field.
Meral I et al. · 2007
In brain tissue, the MDA level increased and GSH level and CAT enzyme activity decreased in EMF-exposed guinea pigs, while vitamins A, E, and D3 levels did not change. In blood, MDA, vitamins A, D3, and E levels, and CAT enzyme activity increased, while GSH level decreased in the EMF-exposed guinea pigs.
Unknown authors · 2006
PMA treatment significantly increased ROS production in both cell types compared to sham or incubator controls. GSM-DTX exposure showed significantly different ROS production in monocytes compared to sham, but this was due to lowered ROS release during sham exposure. No ROS differences were detected in lymphocytes compared to sham or incubator control. Hsp70 expression in monocytes at 0, 1, and 2 hours post-exposure to GSM-DTX at 2 W/kg for 1 hour did not differ from incubator or sham controls.
Unknown authors · 2006
Researchers investigated the effect of acute UHF-EMF exposure on non-enzymatic antioxidant defense and lipid and protein oxidative damage in the rat frontal cortex and hippocampus. They used malondialdehyde (MDA) and carbonyl assays to assess lipid and protein oxidative damages, respectively. No changes in lipid and protein damage, and also in non-enzymatic defense were found in frontal cortex or hippocampus. The results suggest that acute UHF-EMF exposure is not able to produce detectable oxidative stress in rats from any age tested.
Sanchez S et al. · 2006
Apoptosis was not induced in isolated cells and reconstructed epidermis thickness and proliferation were unchanged. No change in heat shock protein expression was observed in isolated keratinocytes. A slight but significant increase in Hsp70 expression was observed in reconstructed epidermis after 3 and 5 weeks of culture. Fibroblasts showed a significant decrease in Hsc70 depending on culture conditions.
Simkó M et al. · 2006
The study investigated Hsp70 expression and free radical release in human Mono Mac 6 cells exposed to ultrafine particles and radiofrequency electromagnetic fields. Ultrafine particle exposure increased free radical release by 40-45% above negative control, an effect stronger than heat treatment. Radiofrequency electromagnetic field exposure alone did not change free radical levels. Combined exposure to RF and ultrafine particles did not enhance the particle effect on free radicals. Heat treatment increased Hsp70 expression in a time-dependent manner, while ultrafine particles, RF fields, or their combination had no effect on Hsp70.
Lantow M, Lupke M, Frahm J, Mattsson MO, Kuster N, Simko M. · 2006
The study investigated whether 1,800 MHz RF-EMF can induce ROS release or Hsp70 expression changes in human blood cells using various exposure conditions. PMA treatment significantly increased ROS production in both monocytes and lymphocytes compared to sham or incubator controls. GSM-DTX exposure at 2 W/kg produced a significant difference in monocyte ROS compared to sham, but this was attributed to lower ROS values in the sham condition, while lymphocytes showed no ROS changes. Hsp70 expression in monocytes did not differ after GSM-DTX exposure at 2 W/kg for 1 hour compared to incubator or sham controls at any post-exposure time point.
Lantow M, Schuderer J, Hartwig C, Simko M. · 2006
Heat and PMA treatment significantly increased superoxide radical anions and ROS production in Mono Mac 6 cells. No significant differences in free radical production were detected after RF EMF exposure compared to controls. The GSM-DTX signal at 2 W/kg showed a significant difference versus sham due to a decreasing sham value, but this difference disappeared when compared to incubator controls. No significant effects on HSP70 expression were detected after RF EMF exposures.
Túnez I et al. · 2006
Researchers investigated the effect of transcranial magnetic field stimulation on free radical production and neuronal cell loss caused by 3-nitropropionic acid in rats. 3-nitropropionic acid induced oxidative and nitrosative stress in the striatum and prompted cell loss. Transcranial magnetic stimulation prevented the harmful effects induced by the acid.
Oral B et al. · 2006
Researchers examined oxidative stress from a 900-MHz mobile phone and the possible protective effects of vitamins E and C on endometrial tissue in rats. Rats were divided into a sham control group, a 900-MHz EMF-exposed group (30 minutes daily for 30 days), and an EMF-exposed group treated with vitamins E and C before each exposure. Malondialdehyde, a marker of lipid peroxidation, and the proteins Bcl-2, Bax, caspase-3, and caspase-8 were measured in endometrial tissue. The EMF-exposed rats showed increased malondialdehyde levels and apoptosis, while vitamins E and C ameliorated oxidative tissue injury and apoptosis through free radical scavenging and antioxidant properties.
Koylu H, Mollaoglu H, Ozguner F, Nazyroglu M, Delibab N. · 2006
Twenty-eight Sprague-Dawley male rats were randomly divided into three groups: sham control, 900-MHz microwave exposure, and microwave exposure with melatonin treatment. Microwave exposure increased lipid peroxidation in both the brain cortex and hippocampus compared to controls. Melatonin administration decreased lipid peroxidation in the hippocampus but did not affect cortex levels.
Calota V, Dragoiu S, Meghea A, Giurginca M · 2006
Researchers investigated the decrease of luminol chemiluminescence upon exposure of human blood serum to 50 Hz electric fields. After 1 and 2 hours of in vitro exposure to 50 Hz electric fields of different intensities, the chemiluminescence of luminol decreased compared to controls. The authors indicate this reflects a field-induced decrease in free radical concentration.
Bediz CS, Baltaci AK, Mogulkoc R, Oztekin E. · 2006
Twenty-four male Sprague-Dawley rats were randomly allocated to three groups: control, EMF-exposed (50 Hz, 5 minutes every other day for 6 months), and EMF-exposed with zinc sulfate (3 mg/kg/day intraperitoneally). Researchers measured plasma zinc and TBARS, and GSH in erythrocytes; TBARS and GSH were also determined in brain tissues. TBARS levels in plasma and brain were higher in EMF-exposed rats than controls, and lower in zinc-supplemented rats than EMF-exposed rats. GSH levels decreased in brain and erythrocytes of EMF-exposed rats and were highest in zinc-supplemented rats. Plasma zinc was lower in EMF-exposed rats than controls and highest in zinc-supplemented rats.
Wang J et al. · 2006
Researchers exposed A172 cells to 2450 MHz high-frequency electromagnetic fields at SARs of 5-200 W/kg and included heat controls at 38-44°C. HSP70 expression increased in a time- and dose-dependent manner at SARs above 50 W/kg for 1-3 hours, similar to heat controls. HSP27 expression did not change significantly with HFEMF exposure or heating, but HSP27 phosphorylation increased transiently at 100 and 200 W/kg, exceeding the effect of heating at 40-44°C, peaking after 1 hour at 100 W/kg.
Yurekli AI et al. · 2006
Researchers used a gigahertz transverse electromagnetic (GTEM) cell to expose rats to electromagnetic fields at the GSM base transceiver station frequency of 945 MHz. The power density applied was 3.67 W/m2 (specific absorption rate = 11.3 mW/kg), which the researchers described as well below current exposure limits. MDA levels increased and GSH concentrations decreased significantly (p < 0.0001) under this exposure. There was also a less significant (p = 0.0190) increase in SOD (superoxide dismutase) activity under EM exposure.
Ozguner F, Bardak Y, Comlekci S. · 2006
Researchers compared how well melatonin and caffeic acid phenethyl ester (CAPE) protected rat retinas from oxidative stress caused by exposure to 900 MHz mobile-phone radiation. Melatonin and CAPE were administered daily for 60 days to the rats prior to their EMR exposure. Retinal levels of the oxidative stress markers NO and MDA increased in EMR-exposed rats, while both melatonin and CAPE caused a significant reduction in those levels. Antioxidant enzyme activities (SOD, GSH-Px, and CAT) decreased in EMR-exposed animals, but both treatments significantly increased those activities.
Jelenković A et al. · 2006
Researchers exposed adult male Wistar rats to a 50 Hz, 0.5 mT extremely low-frequency magnetic field for 7 days, while control rats were sham-exposed. Superoxide dismutase activities and production of superoxide radicals, lipid peroxidation, and nitric oxide were examined in the frontal cortex, striatum, basal forebrain, hippocampus, brainstem, and cerebellum. Superoxide radicals were significantly increased in all regions examined, and lipid peroxidation was significantly increased in the basal forebrain and frontal cortex. The researchers indicated that the 7-day exposure can be harmful to the brain, especially to the basal forebrain and frontal cortex due to development of lipid peroxidation.
Frahm J, Lantow M, Lupke M, Weiss DG, Simkó M · 2006
Researchers investigated whether extremely low frequency electromagnetic fields affect cellular functions and immunologic parameters of mouse macrophages. Magnetic field exposure led to a 1.6-fold increased uptake of latex beads in exposed cells compared to controls after 45 minutes. IL-1β formation increased significantly after 4 hours and reached a maximum 12.3-fold increase after 24 hours compared to controls. All tested flux densities significantly stimulated free radical formation, and no significant differences in micronucleus formation were found in exposed cells.
De Nicola M et al. · 2006
Researchers exposed U937 cells to static magnetic fields at 6 mT and found a strong increase of reactive oxygen species and a decrease of glutathione levels after 2 hours of exposure. Extremely-low-frequency magnetic fields also affected intracellular glutathione, starting from a threshold at 0.09 mT. ELF magnetic fields protected U937 from apoptosis, but this ability was limited to the ELF intensities able to alter redox equilibrium. When the cells' redox state was artificially altered, magnetic fields failed to affect apoptosis, suggesting a correct intracellular redox state is required for the antiapoptotic effect.
Aksen F, Akdag MZ, Ketani A, Yokus B, Kaya A, Dasdag S. · 2006
Unknown authors · 2005
Researchers studied singlet oxygen production sensitized by chemically modified, carotenoidless bacterial photosynthetic reaction centres. Both the singlet oxygen yield and the ensuing oxidative damage were shown to depend on magnetic field.
Unknown authors · 2005
Researchers exposed insulin solution to a pulsed electric field of 0.7 V/m at 50 Hz for 20 minutes and then added it to human hepatocyte cultures. They investigated insulin signaling events including ligand-receptor binding, tyrosine phosphorylation, gene transcription, and cell proliferation using multiple methods. PEF exposure caused a conformational change in insulin, reduced its receptor binding capacity to 87% of control, and decreased intracellular tyrosine phosphorylation by 11%. The expression of 55 out of 12000 genes was altered, including increased expression of human tyrosine phosphatase and a small GTP-binding protein.
Unknown authors · 2005
The study used molecular dynamics simulations to examine insulin chain-B under static and oscillating electric fields ranging from 10(7) to 10(9) V/m. Both field types affected the protein's normal behavior, with oscillating fields being more disruptive to structure than static fields of similar strength. Static fields stabilized the secondary structure but restricted the inherent flexibility required for insulin's biological activity.
Lee JS, Huang TQ, Lee JJ, Pack JK, Jang JJ, Seo JS. · 2005
Researchers exposed eight-week-old hsp70.1-deficient mice twice daily for 45 minutes with a 15-minute interval, five days a week for ten weeks at a whole-body average specific absorption rate of 0.4 W/Kg for both 849 MHz and 1763 MHz fields. They examined major tissues histopathologically, assessed cell proliferative activity immunocytochemically, measured apoptosis with a TUNEL assay, and evaluated heat shock protein expression and stress-activated kinase phosphorylation by western blot. No histopathological differences were found between sham- and RF-exposed mice, and there was no evidence of increased proliferative or apoptotic activity. Levels of HSP90, HSP70, and HSP25 showed no obvious changes, and RF exposure did not affect phosphorylation of ERK1/2, JNK1/2, or p38 MAPK.
Harakawa S et al. · 2005
The effects of exposure to extremely low frequency electric fields (ELF EFs) on plasma lipid peroxide levels and antioxidant activity (AOA) in Sprague–Dawley rats were studied. The test compared rats treated with a combination of the oxidizing agent AAPH and a 50 Hz EF of 17.5 kV/m for 15 min per day for 7 days, as well as AAPH alone, EF alone, or no treatment. EF significantly decreased the plasma peroxide level in rats treated with AAPH, similar to treatment by ascorbic acid or the superoxide dismutase.
