Electromagnetic Field Group Research Articles

Combined Exposure of Peripubertal Male Rats to the Endocrine-Disrupting Compound Atrazine and Power–Frequency Electromagnetic Fields Causes Degranulation of Cutaneous Mast Cells: A New Toxic Environmental Hazard?

The effects of single and combined treatments of the endocrine-disrupting compound atrazine and the power-frequency electromagnetic fields (EMFs) were investigated on cutaneous mast cells in juvenile/peripubertal male Wistar rats. Animals were divided into six groups: (1) 4 h/day exposure to EMFs (50 Hz), (2) 20 mg/kg of body weight (bw) of atrazine, (3) 200 mg/kg bw of atrazine, (4) EMFs with 20 mg/kg bw of atrazine, (5) EMFs with 200 mg/kg bw of atrazine, and (6) control. Both the atrazine and the combined treatments, but not the single EMF exposure, increased the number of degranulated mast cells. Statistically significant differences were demonstrated between the control and both of the combined treatments (p<0.01 and p<0.001, respectively). Additionally, low and high doses of atrazine combined with the EMFs were found significantly different when compared to the EMF group alone (both at p<0.001). Considering the biological importance of mast cells in cutaneous immune reactions, future studies should reveal whether combined exposures to chemical and physical environmental agents pose a serious health risk.

Pulsed Electromagnetic Field Stimulates Cellular Proliferation in Human Intervertebral Disc Cells

PurposeThe purpose of this study is to investigate the mechanism of cellular proliferation of electromagnetic field (EMF) on human intervertebral disc (IVD) cells.Materials and MethodsHuman IVD cells were cultured three-dimensionally in alginate beads. EMF was exposed to IVD cells with 650Ω, 1.8 millitesla magnetic flux density, 60 Hz sinusoidal wave. Cultures were divided into a control and EMF group. Cytotoxicity, DNA synthesis and proteoglycan synthesis were measured by MTT assay, [3H]-thymidine, and [35S]-sulfate incorporation. To detect phenotypical expression, reverse transcription-polymerase chain reactions (RT-PCR) were performed for aggrecan, collagen type I, and type II mRNA expression. To assess action mechanism of EMF, IVD cells were exposed to EMF with NG-Monomethyl-L-arginine (NMMA) and acetylsalicylic acid (ASA).ResultsThere was no cytotoxicity in IVD cells with the EMF group in MTT assay. Cellular proliferation was observed in the EMF group (p < 0.05). There was no difference in newly synthesized proteoglycan normalized by DNA synthesis between the EMF group and the control. Cultures with EMF showed no significant change in the expression of aggrecan, type I, and type II collagen mRNA compared to the control group. Cultures with NMMA (blocker of nitric oxide) or ASA (blocker of prostaglandin E2) exposed to EMF demonstrated decreased DNA synthesis compared to control cultures without NMMA or ASA (p < 0.05).ConclusionEMF stimulated DNA synthesis in human IVD cells while no significant effect on proteoglycan synthesis and chondrogenic phenotype expressions. DNA synthesis was partially mediated by nitric oxide and prostaglandin E2. EMF can be utilized to stimulate proliferation of IVD cells, which may provide efficient cell amplification in cell therapy to degenerative disc disease.

The protective effect of caffeic acid phenethyl ester (CAPE) on oxidative stress in rat liver exposed to the 900 MHz electromagnetic field

In this study, we aimed to investigate the possible protective effects of caffeic acid phenethyl ester (CAPE) on lipid peroxidation (LPO) and the activities of antioxidant enzymes in the liver of rats exposed to the 900 MHz electromagnetic field (EMF). EMF of cellular phones may affect biological systems by increasing free radical, which appear mainly to enhance LPO, and by changing the antioxidative activities of liver, thus leading to oxidative damage. CAPE, an active component of propolis extract, exhibits antioxidant properties and several studies suggest that supplementation with antioxidant can influence EMF exposure induced hepatotoxicity. Thirty male Sprague-Dawley rats were divided into three groups: control (n = 10), 900 MHz EMF (n = 10) and 900 MHz EMF + CAPE (n = 10). CAPE was injected intraperitoneally for 30 days before exposure to EMF. Liver tissue was removed to study the activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), xanthine oxidase (XO) and the levels of LPO. The activities of XO, CAT and level of LPO increased in the 900 MHz electromagnetic field (EMF) group compared with the control group, although XO, CAT activities and LPO levels were decreased by 900 MHz EMF + CAPE administration. The activities of SOD and GSH-Px decreased in the 900 MHz EMF group compared with the control group, although their levels were increased by EMF + CAPE administration. It can be concluded that CAPE may prevent the 900 MHz EMF-induced oxidative changes in liver by strengthening the antioxidant defense system by reducing reactive oxygen species and increasing antioxidant enzyme activities.

Can low frequency electromagnetic field help cartilage tissue engineering?

To understand whether a low-frequency pulsed electromagnetic field (EMF) could help cartilage tissue repair in the scope of tissue engineering, we tested how EMF affected collagen gel properties and the behaviors of chondrocyte cells embedded in collagen constructs. Collagen gel and primary chondrocytes embedded in collagen were exposed to EMF for 24 h. Gel and cells that were not exposed to EMF served as controls. Collagen gel exposed to EMF was more hydrophobic and less susceptible to enzymatic degradation (both p < 0.05) than control. Three weeks after EMF exposure, chondrocytes showed higher proliferation and lower glycosaminoglycan (GAG) production (both p < 0.05) than control. By the end of the third week, aggrecan, type I, II, and X collagen mRNA expressions in the EMF group were 1.8 times higher (p < 0.05), except for type II collagen) than control. The increase in gene expression did not show up in aggrecan histological staining and type II and type X collagen immunohistochemical staining. Cells from both groups kept a normal polygonal shape through out the test period. Our results suggested that one-time EMF exposure could promote collagen-embedded chondrocytes proliferation and their gene expressions. It also promoted short-term (week 1) GAG production and lacuna formation. No apparent GAG and type II collagen production was seen in histological staining three weeks after the EMF exposure.

900 MHz electromagnetic field exposure affects qualitative and quantitative features of hippocampal pyramidal cells in the adult female rat

The effects of electromagnetic fields (EMFs) emitted by mobile phones on humans hold special interest due to their use in close proximity to the brain. The current study investigated the number of pyramidal cells in the cornu ammonis (CA) of the 16-week-old female rat hippocampus following postnatal exposure to a 900 megahertz (MHz) EMF. In this study were three groups of 6 rats: control (Cont), sham exposed (Sham), and EMF exposed (EMF). EMF group rats were exposed to 900 MHz EMF (1 h/day for 28 days) in an exposure tube. Sham group was placed in the exposure tube but not exposed to EMF (1 h/day for 28 days). Cont group was not placed into the exposure tube nor were they exposed to EMF during the study period. In EMF group rats, the specific energy absorption rate (SAR) varied between 0.016 (whole body) and 2 W/kg (locally in the head). All of the rats were sacrificed at the end of the experiment and the number of pyramidal cells in the CA was estimated using the optical fractionator technique. Histopathological evaluations were made on sections of the CA region of the hippocampus. Results showed that postnatal EMF exposure caused a significant decrease of the pyramidal cell number in the CA of the EMF group ( P < 0.05). Additionally, cell loss can be seen in the CA region of EMF group even at qualitative observation. These results may encourage researchers to evaluate the chronic effects of 900 MHz EMF on teenagers' brains.

Effects of prenatal exposure to a 900 MHz electromagnetic field on the dentate gyrus of rats: a stereological and histopathological study

Electromagnetic fields (EMFs) inhibit the formation and differentiation of neural stem cells during embryonic development. In this study, the effects of prenatal exposure to EMF on the number of granule cells in the dentate gyrus of 4-week-old rats were investigated. This experiment used a control (Cont) group and an EMF exposed (EMF) group (three pregnant rats each group). The EMF group consisted of six offspring ( n = 6) of pregnant rats that were exposed to an EMF of up to 900 megahertz (MHz) for 60 min/day between the first and last days of gestation. The control group consisted of five offspring ( n = 5) of pregnant rats that were not treated at all. The offspring were sacrificed when they were 4 weeks old. The numbers of granule cells in the dentate gyrus were analyzed using the optical fractionator technique. The results showed that prenatal EMF exposure caused a decrease in the number of granule cells in the dentate gyrus of the rats ( P < 0.01). This suggests that prenatal exposure to a 900 MHz EMF affects the development of the dentate gyrus granule cells in the rat hippocampus. Cell loss might be caused by an inhibition of granule cell neurogenesis in the dentate gyrus.

Effects of Electromagnetic Field on Thyroid Functions in Rats

The effect of electromagnetic field (EMF) on serum thyroid stimulating hormone (TSH) and triiodothyronine-thyroxin (T3-T4) hormones levels of adult male Sprague-Dawley rats were studied. Fifty rats were used in three independent groups, 20 of which were control (without stress and EMF), 20 of which were exposed to 900 MHz EMF and 10 of which were sham-exposed. The exposures were performed 30 min/day, for 5 days/week for 4 weeks to 900 MHz EMF. Sham-exposed animals were kept under the same environmental conditions as the study groups except with no EMF exposure. The concentration of TSH and T3-T4 hormones in the rat serum was measured by using an enzyme liked immunsorbent assay (ELISA) method for TS, T3, and T4 hormones. TSH values and T3-T4 at the 900 MHz EMF group were significantly lower than the sham-exposed group (p 0.05). These results indicate that 900 MHz EMF emitted by cellular telephones decrease serum TSH and T3-T4 levels.

Light and electron microscopic study of the thyroid gland in rats exposed to power-frequency electromagnetic fields

The effect of 50 Hz electromagnetic field (EMF) on thyroid gland was studied using light and transmission electron microscopes. Two-month-old male rats were exposed to an EMF (100-300 microT, 54-160 V m(-1)) for 4 h a day, 5 days a week for 1 month. A predominance of microfollicles with less colloid content and dilated blood capillaries was found in the EMF group. Stereological counting showed a statistically significant increase of the volume density of follicular epithelium, interfollicular tissue and blood capillaries as well as the thyroid activation index, as compared to the controls. The volume density of colloid significantly decreased. Ultrastructural analysis of thyroid follicular cells in the EMF group revealed the frequent finding of several colloid droplets within the same thyrocyte with the occasional presence of large-diameter droplets. Alterations in lysosomes, granular endoplasmic reticulum and cell nuclei compared to the control group were also observed. Taken together, the results of this study show the stimulative effect of power-frequency EMF on thyroid gland at both the light microscope and the ultrastructural level.

No effects of 900 MHz and 1800 MHz electromagnetic field emitted from cellular phone on nocturnal serum melatonin levels in rats

In this study, the effects of exposure to a 900 MHz and 1800 MHz electromagnetic field (EMF) on serum nocturnal melatonin levels of adult male Sprague-Dawley rats were studied. Thirty rats were used in three independent groups, 10 of which were exposed to 900 MHz, 10 of which were exposed to 1800 MHz and 10 of which were sham-exposed (control). The exposures were performed 30 min/day, for five days/week for four weeks to 900 MHz or 1800 MHz EMF Control animals were kept under the same environmental conditions as the study groups except with no EMF exposure. The concentration of nocturnal melatonin in the rat serum was measured by using a radioimmunoassay method. There were no statistically significant differences in serum melatonin concentrations between the 900 MHz EMF group and the sham-exposed group (P > 0.05). The values at 12:00 pm were 39.11 +/- 6.5 pg/mL in the sham-exposed group and 34.97 +/- 5.1 pg/mL in the 900 MHz EMF-exposed group. Also, there were no statistically significant differences in serum melatonin concentrations between the sham-exposed group and the 1800 MHz EMF-exposed group (P > 0.05). The values at 12:00 pm were 39.11 +/- 6.5 pg/mL in the sham-exposed group and 37.96 +/- 7.4 pg/mL in the exposed group. These results indicate that mobile phones, emitting 900 and 1800 MHz EMF, have no effect on nocturnal serum melatonin levels in rats.

Nitric oxide level in the nasal and sinus mucosa after exposure to electromagnetic field

The purpose of this study was to examine the changes in nitric oxide (NO) level in the nasal and paranasal sinus mucosa after exposure radiofrequency electromagnetic fields (EMF). Thirty male Sprague-Dawley rats were randomly grouped as follows: EMF group (group I; n, 10), EMF group in which melatonin received (group II; n, 10) and the control (sham operated) group (group III; n, 10). Groups I and II were exposed to a 900 MHz. Oral melatonin was given in group II. Control rats (group III) were also placed in the tube as the exposure groups, but without exposure to EMF. At the end of 2 weeks, the rats were sacrificed, and the nasal and paranasal sinus mucosa dissected. NO was measured in nasal and paranasal mucosa. The nasal and paranasal sinus mucosa NO levels of group I were significantly higher than those of the control group (group III) ( P < 0.05). However, there was no statistically significant difference between group II and the control group (group III) regarding NO output ( P > 0.05). Exposure to EMF released by mobile phones (900 MHz) increase NO levels in the sinus and nasal mucosa. Increased NO levels may act as a defense mechanism and presumably related to tissue damage. In addition, melatonin may have beneficial effect to prevent these changes in the mucosa.

Effects of 900 MHz electromagnetic field on TSH and thyroid hormones in rats

In this study, the effects of exposure to a 900 megahertz (MHz) electromagnetic field (EMF) on serum thyroid stimulating hormone (TSH) and triiodothronine–thyroxin (T 3–T 4) hormones levels of adult male Sprague–Dawley rats were studied. Thirty rats were used in three independent groups, 10 of which were control (without stress and EMF), 10 of which were exposed to 900 MHz EMF and 10 of which were sham-exposed. The exposures were performed 30 min/day, for 5 days/week for 4 weeks to 900 MHz EMF. Sham-exposed animals were kept under the same environmental conditions as the study groups except with no EMF exposure. The concentration of TSH and T 3–T 4 hormones in the rat serum was measured by using an immunoradiometric assay (IRMA) method for TSH and a radio-immunoassay (RIA) method for T 3 and T 4 hormones. TSH values and T 3–T 4 at the 900 MHz EMF group were significantly lower than the sham-exposed group ( p < 0.01). There were no statistically significant differences in serum TSH values and T 3–T 4 hormone concentrations between the control and the sham-exposed group ( p > 0.05). These results indicate that 900 MHz EMF emitted by cellular telephones decrease serum TSH and T 3–T 4 levels.

The Effect of Pulsed Electromagnetic Field in Human Intervertebral Disc Cell

Study design: An in vitro experiment. Objectives: To assess the effect of pulsed sinusoidal EMF on human intervertebral disc (IVD) cells. Literature Review Summary: Electromagnetic field (EMF) is known to modify some relevant physiological parameters of cells cultured in vitro, such as proliferation, synthesis, secretion of growth factors and transcription. EMF induces bone formation in delayed, non union and spinal fusion models. Also, the exposure of EMF has been shown to protect against the hazardous effect of smoking in the rabbit IVD. Materials and Methods: Human IVD cells were three-dimensionally cultured in alginate beads and exposed to a 650Ω, 1.8millitesla magnetic flux density, 60Hz sinusoidal wave of EMF. The cultures were divided into the control and EMF groups, with various exposure times. The cytotoxicity, and DNA and proteoglycan syntheses were measured by the MTT assay, and [3H]thymidine and [35S]-sulfate incorporation, respectively. RT-PCRs were performed for aggrecan, and collagen types I and II mRNA expressions. Results: There was no recognizable cytotoxicity in the EMF group, but cellular proliferation was stimulated (p<0.05). Newly synthesized proteoglycan, normalized by DNA synthesis, was decreased in the EMF group (p<0.05) as were the expressions of aggrecan (48hour exposure) and type II collagen (72 hours exposure) mRNA compared to the control group. Conclusions: EMF seems to be hazardous in the synthesis of the chondrogenic matrix, while marginally beneficial in the cellular proliferation of human IVD cells.

Effect of electromagnetic fields and early postoperative 5-fluorouracil on the healing of colonic anastomoses.

Studies have indicated a deleterious effect of perioperative 5-fluorouracil (5-FU) administration on the healing of intestinal anastomoses. This study examined the effect of early postoperative 5-FU on the healing of colonic anastomoses and investigated the effect of electromagnetic fields (EMF) on colonic anastomotic repair under normal physiological conditions and in the presence of 5-FU therapy in a rat model. Forty male Wistar rats were randomly assigned into four groups and underwent a standardized left colonic resection and anastomoses. The animals then served as control or received intraperitoneal 5-FU (20 mg/kg per day, 5 days), EMF stimulation (10.76 mT, 50 Hz; 2-h on/10-h off cycles, 7 days) or both, starting on the day of surgery. After 7 days anastomotic healing was assessed by measurement of hydroxyproline content and breaking strength. Hydroxyproline content increased in EMF exposed group (1.53+/-0.11 to 1.92+/-0.11 microg/mg) and in EMF + 5-FU group (1.53+/-0.11 to 1.89+/-0.12 microg/mg). Breaking strength also increased in the EMF group (0.23+/-0.02 to 0.27+/-0.01 MPa) and in the EMF + 5-FU group (0.23+/-0.02 to 0.28+/-0.01 MPa. No differences were found in hydroxyproline content or breaking strength between the 5-FU group and controls. Early postoperative 5-FU administration did not impair the healing of colonic anastomoses in rats. Additionally, EMF stimulation provided a significant gain in colonic anastomotic strength, in rat intestines in control animals and in animals exposed to 5-FU.

BEHAVIOR OF FREE-RANGING AND CAPTIVE AMERICAN KESTRELS UNDER ELECTROMAGNETIC FIELDS

Wild birds, particularly raptors, commonly use electrical transmission structures for nesting, perching, hunting, and roosting. Consequently, birds are exposed to electromagnetic fields (EMFs). The amount of time that wild reproducing American kestrels (Falco sparverius) were exposed to EMFs was determined, and the effects of EMFs on the behavior of captive reproducing kestrels were examined. Wild kestrels were exposed to EMFs for 25% to 75% of the observed time. On a 24-h basis, estimated EMF exposure of wild kestrels ranged from 71% during courtship, to 90% during incubation, similar to that experienced by captive kestrels (88% of a 24-h period). Additionally, captive kestrels were exposed to EMF levels experienced by wild kestrels nesting under 735-kV power lines. Captive EMF females were more active, more alert, and perched on the pen roof more frequently than control females during courtship. EMF females preened and rested less often during brood rearing. EMF male kestrels were more active than control males during courtship, and more alert during incubation. Increased activity of kestrels during courtship may be linked to changes in corticosterone, but likely not melatonin. Observed behavioral changes were unlikely to directly result in the better growth of nestlings and fledging success, or poorer hatching success, of the EMF group, as previously reported. Behavioral changes of captive EMF kestrels may be observed in wild kestrels.

Effect of 60-HZ Sinusoidal Electromagnetic Field on Avian Embryonic Growth and Oxygen Consumption

Domestic fowl embryonic oxygen consumption, organ growth and maturity, and growth abnormalities were studied after exposure to 2-, 1-, and 0.5-gauss (G) 60-Hz sinusoidal electromagnetic fields (EMF), throughout incubation. Embryonic growth and oxygen consumption increased after exposure to a 2-G EMF but they were inhibited by I-G EMF. There were no significant biological effects of 0.5-G EMF on embryonic growth and oxygen consumption. Deformities were found in the 2-G and 1-G EMF groups but only in the 2-G group did they reach a statistically significant level. There were no deformities in the 0.543 EMF group or any of the control groups. Pectoral muscles were most affected by an EMF of 2 G, while the intestine was largely spared the enhanced growth. The intestine was also spared the repression of growth at an EMF of 1 G; the lungs were most affected. Enhanced organ growth was associated with increased tissue maturity, particularly in pectoral muscles. The effects of a 1-G EMF on organ maturity were small...