Evaluation of the influence of in vivo exposure to extremely low-frequency magnetic fields on the plasma levels of pro-inflammatory cytokines in rats

Abstract

Purpose: Epidemiological data suggest that there is a link between exposure to extremely low-frequency magnetic fields (ELF-MFs), immune response, and the occurrence of neurodegenerative diseases. The exact nature of this phenomenon remains speculative and requires detailed laboratory investigation. In the present study, we evaluate changes in plasma concentration of pro-inflammatory and regulatory cytokines as well as alternations of the hematological parameters in rats exposed to an ELF-MF.

Materials and methods: Male Wistar rats were repeatedly exposed for either 1 h/day for 7 days, or continuously for 24 h, to a sinusoidal ELF-MF (50 Hz, 7 mT). Control groups were sham exposed for either 1 h/day for 7 days, or continuously for 24 h, respectively. The levels of cytokines: interleukin (IL)-1β, IL-2, IL-6, and IL-10 in plasma obtained from blood samples were determined using enzyme-linked immunosorbent assay (ELISA). The changes in blood parameters were determined using an automatic hematology analyzer in whole blood samples immediately after collection.

Results: We found that a single continuous (lasting 24 h) exposure provoked a significant increase of the plasma IL-1β, IL-6, and IL-2 levels, and caused an elevation in blood parameters, such as white blood cells, lymphocytes, hemoglobin, and hematocrit levels. In contrast, however, repetitive exposure of rats to an ELF-MF for 1 h/day for 7 days did not lead to any changes in plasma levels of cytokines and hematological counts.

Conclusions: Based on these data we conclude that exposure duration (dose-response) plays a significant role in the immune response, specifically at the cellular level. While single 24 h-lasting exposure provoked changes that indicate an immune alarm stimulation, under the conditions which are typical for therapeutic use of ELF-MFs (repeated short daily exposure) the immune potentially harmful response has not been observed.

Keywords:

• Extremely low-frequency magnetic field
• cytokines
• hematological parameter
• rat

Acknowledgment

The authors would like to thank Donovan Kelorii (LSBA, CELTA) for constructive criticism and copy editing of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Nicolaus Copernicus University (Toru?, Poland) [Intramural Grants: 1527-B and 1925-B to Tomasz Jedrzejewski and 1539-B to Joanna Wyszkowska].

Notes on contributors

Joanna Wyszkowska

Joanna Wyszkowska is an assistant professor at the Department of Biophysics at Nicolaus Copernicus University in Torun.

Tomasz Jędrzejewski

Tomasz Jedrzejewski is an assistant professor at the Department of Immunology at Nicolaus Copernicus University in Torun.

Jakub Piotrowski

Jakub Piotrowski is a scientific and technical specialist at the Department of Immunology at Nicolaus Copernicus University in Torun.

Anna Wojciechowska

Anna Wojciechowska is an assistant professor at the Chair of Geobotany and Landscape Planning at Nicolaus Copernicus University in Torun.

Maria Stankiewicz

Maria Stankiewicz is a tenured professor of biophysics and physiology, and Head of the Department of Biophysics at Nicolaus Copernicus University in Torun.

Wieslaw Kozak

Wieslaw Kozak is a tenured professor of physiology and immunology, and Head of the Department of Immunology at Nicolaus Copernicus University in Torun.