Effects of electromagnetic pulse on serum element levels in rat

Electromagnetic fields regulate iron metabolism in living organisms: A review of effects and mechanism

The emergence, evolution, and spread of life on Earth have all occurred in the geomagnetic field, and its extensive biological effects on living organisms have been documented. The charged characteristics of metal ions in biological fluids determine that they are affected by electromagnetic field forces, thus affecting life activities. Iron metabolism, as one of the important metal metabolic pathways, keeps iron absorption and excretion in a relatively balanced state, and this process is precisely and completely controlled. It is worth paying attention to how the iron metabolism process of living organisms is changed when exposed to electromagnetic fields. In this paper, the processes of iron absorption, storage and excretion in animals (mammals, fish, arthropods), plants and microorganisms exposed to electromagnetic field were summarized in detail as far as possible, in order to discover the regulation of iron metabolism by electromagnetic field. Studies and data on the effects of electromagnetic field exposure on iron metabolism in organisms show that exposure profiles vary widely across species and cell lines. This process involves a variety of factors, and the complexity of the results is not only related to the magnetic flux density/operating frequency/exposure time and the heterogeneity of the observed object. A systematic review of the biological regulation of iron metabolism by electromagnetic field exposure will not only contributes to a more comprehensive understanding of its biological effects and mechanism, but also is necessary to improve human awareness of the health related risks of electromagnetic field exposure.

Trace elements homeostasis in brain exposed to 900 MHz RFW emitted from a BTS-antenna model and the protective role of vitamin E

Advances in telecommunication and their broad usage in the community have become a great concern from the health aspect. The object of the present study was to examine the effects of exposure to 900 MHz RFW on brain Iron (Fe), Copper (Cu), Zinc (Zn) and Manganese (Mn) concentration, and the protective role of pre-treatment of vitamin E on mentioned elements homoeostasis. Twenty adult male Sprague-Dawley rats (200 ± 20 g) randomly were divided into four groups. Control group (without any exposure, received distilled water), treatment control group (orally received 250 mg/kg BW/d vitamin E), treatment group (received 250 mg/kg BW/d vitamin E and exposed to 900 MHz RFW) and sham-exposed group (exposed to 900 MHz RFW). Animals (with freely moving in the cage) were exposed to RFW for 30 consecutive days (4 hr/day). The levels of the above mentioned elements in the brain tissue were determined on the last day using atomic absorption spectrophotometry. Exposure to 900 MHz RFW induced a significant increase in the Fe, Cu, Mn levels and Cu/Zn ratio accompanied by a significant decrease in Zn level in the sham-exposed group compare to control group. Vitamin E pre-treatment improved the level of Fe, Cu, Mn and Cu/Zn ratio, except in the Zn concentration. Exposure to 900 MHz RFW caused disrupted trace elements homoeostasis in the brain tissue and administration of vitamin E as an antioxidant and neuroprotective agent improved the situation.

Alteration of Metal Elements in Radiation Injury: Radiation-Induced Copper Accumulation Aggravates Intestinal Damage

Ionizing radiation causes damage to a variety of tissues, especially radiation-sensitive tissues, such as the small intestine. Radiation-induced damage is caused primarily by increased oxidative stress in the body. Studies have shown that trace metal elements play an irreplaceable role in oxidative stress in humans, which may be associated with radiation-induced tissue damage. However, the alteration and functional significance of trace metal elements in radiation-induced injury is not clear. In this study, we explored the association between radiation-induced damage and 7 trace metal elements in mouse models. We found that the concentration of zinc and copper in mice serum was decreased significantly after irradiation, whereas that of nickel, manganese, vanadium, cobalt, and stannum was not changed by inductively coupled plasma mass spectrometry. The role of copper in radiation-induced intestines was characterized in detail. The concentration of copper was increased in irradiated intestine but reduced in irradiated heart. Immunohistochemistry staining showed that copper transporter protein copper transport 1 expression was upregulated in irradiated mouse intestine, suggesting its potential involvement in radiation-induced copper accumulation. At the cellular level, the addition of CuCl2potentiated radiation-induced reactive oxygen species in intestine-derived human intestinal epithelial cell and IEC-6 cells. Moreover, the level of copper in damaged cells may be related to the severity of radiation-induced damage as evidenced by a cell viability assay. These results indicate that copper may be involved in the progression of radiation-induced tissue damage and may be a potential therapeutic target.

Effects of paternal electromagnetic pulse exposure on the reproductive endocrine function of male offspring: a pilot study

Many studies indicate that parental exposure to an electromagnetic field (EMF) can cause long-term toxicity to the health of the offspring. While concerns have been focused on maternal influence, much less is known regarding the effects of paternal factors. Electromagnetic pulse (EMP) is a special and widely used type of EMF. The present study was designed to investigate the effects of paternal EMP exposure on the reproductive endocrine function of the male rat offspring. Male Sprague Dawley rats were randomly exposed to EMP at 200 kV m-1 for 0, 100 or 400 pulses before mating. The adult male offspring were sacrificed and the structural changes of testes, levels of serum steroid hormones, sperm characteristics, reproductive behaviors, content of the reproductive endocrine-related neurotransmitter GABA and expression of the GABAA receptor were analyzed. The results showed that paternal exposure induced a decrease of testosterone (T), sperm quantity and acrosin activity in the male offspring (p < 0.05). It did not show significant changes in the structure of testes, sperm deformity frequency and reproductive behaviors compared with the sham-exposed group. The content of GABA and the protein and mRNA expression of the hypothalamic GABAA receptor protein increased in the EMP exposure group (p < 0.05). In conclusion, our study shows that under these experimental conditions EMP had a certain degree of influence on the reproductive endocrine function of the male rat offspring, and the hypothalamic GABAA receptor may be involved in the reproductive toxicity of the male offspring.

Extremely low frequency electromagnetic fields promote mesenchymal stem cell migration by increasing intracellular Ca2+ and activating the FAK/Rho GTPases signaling pathways in vitro

Background

The ability of mesenchymal stem cells (MSCs) to migrate to the desired tissues or lesions is crucial for stem cell-based regenerative medicine and tissue engineering. Optimal therapeutics for promoting MSC migration are expected to become an effective means for tissue regeneration. Electromagnetic fields (EMF), as a noninvasive therapy, can cause a lot of biological changes in MSCs. However, whether EMF can promote MSC migration has not yet been reported.

Methods

We evaluated the effects of EMF on cell migration in human bone marrow-derived MSCs. With the use of Helmholtz coils and an EMF stimulator, 7.5, 15, 30, 50, and 70 Hz/1 mT EMF was generated. Additionally, we employed the l-type calcium channel blocker verapamil and the focal adhesion kinase (FAK) inhibitor PF-573228 to investigate the role of intracellular calcium content, cell adhesion proteins, and the Rho GTPase protein family (RhoA, Rac1, and Cdc42) in EMF-mediated MSC migration. Cell adhesion proteins (FAK, talin, and vinculin) were detected by Western blot analysis. The Rho GTPase protein family activities were assessed by G-LISA, and F-actin levels, which reflect actin cytoskeletal organization, were detected using immunofluorescence.

Results

All the 7.5, 15, 30, 50, and 70 Hz/1 mT EMF promoted MSC migration. EMF increased MSC migration in an intracellular calcium-dependent manner. Notably, EMF-enhanced migration was mediated by FAK activation, which was critical for the formation of focal contacts, as evidenced by increased talin and vinculin expression. Moreover, RhoA, Rac1, and Cdc42 were activated by FAK to increase cytoskeletal organization, thus promoting cell contraction.

Conclusions

EMF promoted MSC migration by increasing intracellular calcium and activating the FAK/Rho GTPase signaling pathways. This study provides insights into the mechanisms of MSC migration and will enable the rational design of targeted therapies to improve MSC engraftment.

Electronic supplementary material

The online version of this article (10.1186/s13287-018-0883-4) contains supplementary material, which is available to authorized users.

Effect of electromagnetic fields and antioxidants on the trace element content of rat teeth

The purpose of this study was to examine the possible effect of extremely low-frequency electromagnetic fields (ELF-EMFs), from a high-voltage source, on rat teeth in terms of changes in trace elements (TEs) and the effect of antioxidants (melatonin [MLT] and Ganoderma lucidum [GL]) in counteracting these effects. We used adult male Wistar albino rats with a mean weight of 250–300 g and divided the rats into eight groups. The groups were subjected to an ELF-EMF that was applied with a high-voltage line for 8 hours/day for 26 days (Groups I, II, and III) or 52 days (Groups V, VI, and VII). Groups IV and VIII were the 26- and 52-day control/sham groups, respectively. Groups II and VI were treated with GL, and Groups III and VII were treated with MLT. MLT and GL were administered daily based on the weight of the animals and appropriate standards. At the end of the study, the rats were euthanized, and their anterior teeth were extracted. The teeth were preserved in pure water before evaluating the major TEs. At the end of the study, TE concentrations (in mg/kg) were assessed in the control and test groups. Compared with Group V, statistically significant differences in the concentrations of zinc (Zn) and strontium (Sr) were found for Group VII (ELF-EMF + MLT) (P<0.05). Therefore, ELF-EMF exposure can change the content of certain TEs in teeth and, after administering MLT and GL, the values of some of the TEs return to normal.