Electromagnetic fields (UHF) increase voltage sensitivity of membrane ion channels; possible indication of cell phone effect on living cells

Abstract

The effects of ultra high frequency (UHF) nonionizing electromagnetic fields (EMF) on the channel activities of nanopore forming protein, OmpF porin, were investigated. The voltage clamp technique was used to study the single channel activity of the pore in an artificial bilayer in the presence and absence of the electromagnetic fields at 910 to 990 MHz in real time. Channel activity patterns were used to address the effect of EMF on the dynamic, arrangement and dielectric properties of water molecules, as well as on the hydration state and arrangements of side chains lining the channel barrel. Based on the varied voltage sensitivity of the channel at different temperatures in the presence and absence of EMF, the amount of energy transferred to nano-environments of accessible groups was estimated to address the possible thermal effects of EMF. Our results show that the effects of EMF on channel activities are frequency dependent, with a maximum effect at 930 MHz. The frequency of channel gating and the voltage sensitivity is increased when the channel is exposed to EMF, while its conductance remains unchanged at all frequencies applied. We have not identified any changes in the capacitance and permeability of membrane in the presence of EMF. The effect of the EMF irradiated by cell phones is measured by Specific Absorption Rate (SAR) in artificial model of human head, Phantom. Thus, current approach applied to biological molecules and electrolytes might be considered as complement to evaluate safety of irradiating sources on biological matter at molecular level.

• Biophysics
• electromagnetic field
• ion channel
• voltage clamp

Acknowledgments

The authors greatly appreciate the thoughtful comments and constructive suggestions of Professor Jeremy S. Lee (University of Saskatchewan, Canada) who generously shared his time, helped data analysis with patience and kindly reviewed the manuscript. The efforts and invaluable lasting assistance of our colleague Saeed Hadi Alijanvand (IBB, University of Tehran) is much appreciated. We also thank Eng Sajad Sadeghi (School of Electrical and Computer Engineering, University of Tehran) for his assistance in CST simulations.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

The financial support of the University of Tehran is greatly acknowledged.