Electromagnetic fields and human endocrine system

Extremely low frequency electromagnetic fields (ELF EMF) are commonly present in daily life all over the world. Moreover, EMF are used in the physiotherapy of many diseases because of their beneficial effects. There is widespread public concern that EMF may have potential consequences for human health. Although experimental animal studies indicate that EMF may influence secretion of some hormones, the data on the effects of EMF on human endocrine system are scarce. Most of the results concentrate on influence of EMF on secretion of melatonin. In this review, the data on the influence of EMF on human endocrine system are briefly presented and discussed.     

The neurotropic effects of low-intensity electromagnetic waves in rats with different typological characteristics of higher nervous activity

The effects of the ultralow-intensity electromagnetic fields (EMF, frequency of 4200 and 970 MHz, modulated by a quasistochastic signal in the range of 20-20,000 Hz, power density 15 microW/cm2, specific body absorption rate up to 4.5 mJ/kg) on the reactions of the central nervous system (CNS) of rats with different types of behavior were studied. Some neurochemical and behavioral mechanisms of rats' reactions were investigated. It was shown that the EMF produce pronounced changes in the state and activity of monoaminergic brain systems. These changes, on the whole, correspond to the alterations at the integrative level (predominantly, of the inhibitory character).     

Nonthermal electromagnetic fields and estimation of the probable development of the convulsive syndrome

Development of the convulsive syndrome occurs during exposure to electromagnetic fields (EMFs) during physiotherapy and under conditions of professional work. Some researchers believe that EMFs may have medical effects during the treatment of the epilepsy syndrome. Some publications have noted the development of epileptic convulsions in experiments using EMF exposures at various frequencies. Four conditions that may promote the development of convulsions upon EMF exposure are considered.     

The influence of a low- and high-frequency electromagnetic fields on seeds

It was shown that the exposure of seeds in the rest phase to a low-frequency pulse electromagnetic field leads to substantial changes in seed physiology during germination. The changes at the physiological level in sprouting seeds depend not only on the frequency of the external EMF and its power characteristics but also on the kind of seeds. Low- and high-frequency electromagnetic fields are able to produce a biostimulation effect; however, the mechanisms of its appearance are different in their nature. The biochemical studies of seeds after EMF treatment in the modes resulting in expressed biological effects showed an increase in the activity of alpha-amylase, which testifies an increase in the gibberellin output and in the activity of the hydrolytic enzyme sour phosphatase. The response of seeds to EMF treatment demonstrates the possibility of electromagnetic control of growth processes.     

Exposure to 900 MHz electromagnetic field induces an unbalance between pro-apoptotic and pro-survival signals in T-lymphoblastoid leukemia CCRF-CEM cells

It has been recently established that low-frequency electromagnetic field (EMFs) exposure induces biological changes and could be associated with increased incidence of cancer, while the issue remains unresolved as to whether high-frequency EMFs can have hazardous effect on health. Epidemiological studies on association between childhood cancers, particularly leukemia and brain cancer, and exposure to low- and high-frequency EMF suggested an etiological role of EMFs in inducing adverse health effects. To investigate whether exposure to high-frequency EMFs could affect in vitro cell survival, we cultured acute T-lymphoblastoid leukemia cells (CCRF-CEM) in the presence of unmodulated 900 MHz EMF, generated by a transverse electromagnetic (TEM) cell, at various exposure times. We evaluated the effects of high-frequency EMF on cell growth rate and apoptosis induction, by cell viability (MTT) test, FACS analysis and DNA ladder, and we investigated pro-apoptotic and pro-survival signaling pathways possibly involved as a function of exposure time by Western blot analysis. At short exposure times (2-12 h), unmodulated 900 MHz EMF induced DNA breaks and early activation of both p53-dependent and -independent apoptotic pathways while longer continuous exposure (24-48 h) determined silencing of pro-apoptotic signals and activation of genes involved in both intracellular (Bcl-2) and extracellular (Ras and Akt1) pro-survival signaling. Overall our results indicate that exposure to 900 MHz continuous wave, after inducing an early self-defense response triggered by DNA damage, could confer to the survivor CCRF-CEM cells a further advantage to survive and proliferate.     

Investigation of the spinal cord as a natural receptor antenna for incident electromagnetic waves and possible impact on the central nervous system

The effects of electromagnetic field (EMF) exposure on biological systems have been studied for many years, both as a source of medical therapy and also for potential health risks. In particular, the mechanisms of EMF absorption in the human or animal body is of medical/engineering interest, and modern modelling techniques, such as the Finite Difference Time Domain (FDTD), can be utilized to simulate the voltages and currents induced in different parts of the body. The simulation of one particular component, the spinal cord, is the focus of this article, and this study is motivated by the fact that the spinal cord can be modelled as a linear conducting structure, capable of generating a significant amount of voltage from incident EMF.

In this article, we show, through a FDTD simulation analysis of an incoming electromagnetic field (EMF), that the spinal cord acts as a natural antenna, with frequency dependent induced electric voltage and current distribution. The multi-frequency (100–2400 MHz) simulation results show that peak voltage and current response is observed in the FM radio range around 100 MHz, with significant strength to potentially cause changes in the CNS. This work can contribute to the understanding of the mechanism behind EMF energy leakage into the CNS, and the possible contribution of the latter energy leakage towards the weakening of the blood brain barrier (BBB), whose degradation is associated with the progress of many diseases, including Acquired Immuno-Deficiency Syndrome (AIDS).     

Effects of prenatal exposure to a 900 MHz electromagnetic field on 60-day-old rat testis and epididymal sperm quality

We investigated the effects of exposure in utero to a 900 megahertz (MHz) electromagnetic field (EMF) on 60-day-old rat testis and epididymis. Pregnant rats were divided into control (CG; no treatment) and EMF (EMFG) groups. The EMFG was exposed to 900 MHz EMF for 1 h each day during days 13 ? 21 of pregnancy. Newborn rats were either newborn CG (NCG) or newborn EMF groups (NEMFG). On postnatal day 60, a testis and epididymis were removed from each animal. Epididymal semen quality, and lipid and DNA oxidation levels, apoptotic index and histopathological damage to the testis were compared. We found a higher apoptotic index, greater DNA oxidation levels and lower sperm motility and vitality in the NEMFG compared to controls. Immature germ cells in the seminiferous tubule lumen, and altered seminiferous tubule epithelium and seminiferous tubule structure also were observed in hematoxylin and eosin stained sections of NEMFG testis. Nuclear changes that indicated apoptosis were identified in TUNEL stained sections and large numbers of apoptotic cells were observed in most of the seminiferous tubule epithelium in the NEMFG. Sixty-day-old rat testes exposed to 900 MHz EMF exhibited altered sperm quality and biochemical characteristics.     

Investigation of the spinal cord as a natural receptor antenna for incident electromagnetic waves and possible impact on the central nervous system

The effects of electromagnetic field (EMF) exposure on biological systems have been studied for many years, both as a source of medical therapy and also for potential health risks. In particular, the mechanisms of EMF absorption in the human or animal body is of medical/engineering interest, and modern modelling techniques, such as the Finite Difference Time Domain (FDTD), can be utilized to simulate the voltages and currents induced in different parts of the body. The simulation of one particular component, the spinal cord, is the focus of this article, and this study is motivated by the fact that the spinal cord can be modelled as a linear conducting structure, capable of generating a significant amount of voltage from incident EMF. In this article, we show, through a FDTD simulation analysis of an incoming electromagnetic field (EMF), that the spinal cord acts as a natural antenna, with frequency dependent induced electric voltage and current distribution. The multi-frequency (100-2400?MHz) simulation results show that peak voltage and current response is observed in the FM radio range around 100?MHz, with significant strength to potentially cause changes in the CNS. This work can contribute to the understanding of the mechanism behind EMF energy leakage into the CNS, and the possible contribution of the latter energy leakage towards the weakening of the blood brain barrier (BBB), whose degradation is associated with the progress of many diseases, including Acquired Immuno-Deficiency Syndrome (AIDS).     

Effects of a low-intensity electromagnetic field on fibroblast migration and proliferation

The aim of this study was to test if an extremely weak 1?GHz electromagnetic field (EMF), known to be in resonance with clusters of water molecules, has biological effects on human fibroblasts. We demonstrated that in an in vitro model of wound healing, this EMF can activate fibroblast migration. [(3)H]thymidine incorporation experiments demonstrated that the EMF could also activate fibroblast proliferation. Activation of the expression of human fibroblast growth factor 1 (HFGF1) after EMF exposure showed that molecular wound healing pathways are activated in response to this water-resonant EMF.     

Non-thermal electromagnetic fields and estimation of the convulsive syndrome probable development

There are cases of development of a convulsive syndrome at influence of electromagnetic field (EMF) in physiotherapy practice, and in conditions of a professional work. There is a point of view that EMF can render medical effect at treatment of a epilepsy syndrome. Some publications specify on develop of epilepsy convulsions in experiment at EMF of various frequencies exposure. Four conditions which can promote development of convulsions at EMF exposure are considered.     

Protective effects of luteolin on rat testis following exposure to 900 MHz electromagnetic field

Increasing cell phone use calls for clarification of the consequences of long term exposure to electromagnetic fields (EMF). We investigated the effects of EMF on the testes of 12-week-old rats as well as possible protective effects of luteolin on testis tissue. Twenty-four Wistar albino rats were randomly divided into four groups: control, EMF, luteolin, and EMF + luteolin. The number of Leydig cells, primary spermatocytes and spermatids were reduced in the EMF group compared to the control group. In the EMF + luteolin group, the number of Leydig cells, primary spermatocytes and spermatids was significantly greater than the EMF group. We found an increase in superoxide dismutase (SOD) activity in the EMF group compared to the control group. In the EMF group, we found decreased wet weight of testes and serum testosterone levels compared to the control group. Decreased SOD enzyme activity, and increased serum testosterone levels and weight of the testes were observed in the EMF + luteolin group compared to the EMF group. EMF also affected sperm morphology. We found that in rat testis repeated exposure to 900 MHz EMF caused changes in testicular tissue and that the antioxidant, luteolin, substantially reduced the deleterious effects of EMF.     

Can prenatal exposure to a 900 MHz electromagnetic field affect the morphology of the spleen and thymus,and alter biomarkers of oxidative damage in 21-day-old male rats?

We investigated the effects of a 900 Megahertz (MHz) electromagnetic field (EMF), applied during the prenatal period, on the spleen and thymus of 21-day-old male rat pups. Pregnant Sprague-Dawley rats were divided into control and EMF groups. We applied 900 MHz EMF for 1 h/day to the EMF group of pregnant rats. Newborn male rat pups were removed from their mothers and sacrificed on postnatal day 21. Spleen and thymus tissues were excised and examined. Compared to the control group, thymus tissue malondialdehyde levels were significantly higher in the group exposed to EMF, while glutathione levels were significantly decreased. Increased malondialdehyde and glutathione levels were observed in splenic tissue of rats exposed to EMF, while a significant decrease occurred in superoxide dismutase values compared to controls. Transmission electron microscopy showed pathological changes in cell morphology in the thymic and splenic tissues of newborn rats exposed to EMF. Exposure to 900 MHz EMF during the prenatal period can cause pathological and biochemical changes that may compromise the development of the male rat thymus and spleen.     

Post-continuous whole body exposure of rabbits to 650 MHz electromagnetic fields: effects on liver, spleen, and brain

This study deals with the effects of post (12 or 18 months) whole body continuous (2 years) exposure of rabbits to 650 MHz electromagnetic fields (EMF) that are characteristic of those produced by broadcasting stations, on body weight and body mass, on the morphology of liver, spleen and brain, and on apoptosis rates and glycogen distribution in the liver. Two groups of rabbits were continuously exposed for 2 years to EMF of 650 MHz followed by 12 months (group 1) or 18 months (group 2) of post-exposure; a third group (group 3) was sham exposed. It was shown that the changes in apoptosis rates were conditional during the time of exposure, but not on a specific organ and that the whole body continuous exposure gave rise to modifications whose types and intensities were related to the time of post-exposure (12 or 18 months, respectively), the type of organ, and the individual animal. A number of effects were observed only in group 1, and not in group 2, which suggests some kind of adaptive response or of long-term recovery in the rabbits following continuous exposure to 650 MHz EMF.     

Effects of a low-intensity electromagnetic field on fibroblast migration and proliferation

The aim of this study was to test if an extremely weak 1 GHz electromagnetic field (EMF), known to be in resonance with clusters of water molecules, has biological effects on human fibroblasts. We demonstrated that in an in vitro model of wound healing, this EMF can activate fibroblast migration. [³H]thymidine incorporation experiments demonstrated that the EMF could also activate fibroblast proliferation. Activation of the expression of human fibroblast growth factor 1 (HFGF1) after EMF exposure showed that molecular wound healing pathways are activated in response to this water-resonant EMF.     

EXPOSURE TO 50 HZ ELECTROMAGNETIC FIELDS INDUCES THE PHOSPHORYLATION AND ACTIVITY OF STRESS-ACTIVATED PROTEIN KINASE IN CULTURED CELLS

Protein phosphorylation is one of the important processes of cell signal transduction pathways. To study the effects of 50 Hz electromagnetic field (EMF) on the cell signal transduction process, the phosphorylation of stress-activated protein kinase (SAPK/JNK) extracted from Chinese hamster lung (CHL) cells exposed to 0.4 and 0.8 mT 50 Hz EMF for various durations was measured. A solid-phase kinase assay was used to measure the enzymatic activity of SAPK extracted from cells exposed to 50 Hz EMF at the same magnetic flux density and for only 15 min. The results showed that both 0.4 and 0.8 mT could induce the phosphorylation of SAPK, the phosphorylation of SAPK presented a time-dependent course, and there was a difference between the two intensities. The phosphorylated SAPK enhanced its enzymatic activity. All the data indicated that 50 Hz EMF could activate SAPK in a time- and intensity-dependent manner. The biological effects caused by 50 Hz EMF maybe related to the SAPK signal transduction pathway.     

Nonlinear dynamical law governs magnetic field induced changes in lymphoid phenotype.

The results of many different types of animal and human studies dealing with the biological effects of exposure to low frequency electromagnetic fields (EMFs) have consistently been both positive and negative. We addressed the question of why this pattern had occurred so commonly in biological studies involving exposure to EMFs and hypothesized that it stemmed from the prevalent use of a linear model to characterize what are inherently nonlinear input-output relationships. The hypothesis was tested by analyzing biological data using a novel statistical procedure that could be adjusted to detect either nonlinear or linear effects. The reliability of the procedure was established using positive and negative controls and by comparison with the results obtained from sampling a known nonlinear system. In four independent experiments, male and female mice were exposed continuously to 0.1 or 0.5 mT, 60 Hz, for 175 days, and the effect on 20 immune parameters was measured using flow cytometry and functional assays. In each experiment, EMF exposure resulted in statistically significant changes in lymphoid phenotype when and only when the response of the animals to the fields was analyzed as if it were governed by nonlinear laws. Our results suggest that the pattern of inconsistency in the EMF bioeffects studies is an artifact resulting from an incorrect choice of the conceptual model for the relation between the field and the biological effect it causally determines.     

X‐ray‐induced apoptosis of BEL‐7402 cell line enhanced by extremely low frequency electromagnetic field in vitro

This study was designed to test whether extremely low frequency electromagnetic field (ELF‐EMF) could enhance the apoptosis‐induction effect of X‐ray radiotherapy on liver cancer cell line BEL‐7402 in vitro. EMF exposure was performed inside an energized solenoid coil. X‐ray irradiation was performed using a linear accelerator. Apoptosis rates of BEL‐7402 cells were analyzed using Annexin V‐Fit Apoptosis Detection kit. Apoptosis rates of EMF group and sham EMF group were compared when combined with X‐ray irradiation. Our results suggested that the apoptosis rate of BEL‐7402 cells exposed to low doses of X‐ray irradiation could be significantly increased by EMF. More EMF exposures obtain significantly higher apoptosis rates than fewer EMF exposures when combined with 2 Gy X‐ray irradiation. These findings suggested that ELF‐EMF could augment the cell apoptosis effects of low doses of X‐ray irradiation on BEL‐7402 cells in a synergistic and cumulative way. Bioelectromagnetics 30:163–165, 2009. © 2008 Wiley‐Liss, Inc.