An investigation of the effects of TETRA RF fields on intracellular calcium in neurones and cardiac myocytes

Green AC, Scott IR, Gwyther RJ, Peyman A, Chadwick P, Chen X, Alfadhl Y, Tattersall JE

Int J Radiat Biol. 81(12):869-885, 2005

Purpose: This study aimed to determine whether Terrestrial Trunked Radio (TETRA) fields can affect intracellular calcium signalling in excitable cells.

Materials and methods: Intracellular calcium concentration ([Ca_{2 +} ](i)) was measured in cultured rat cerebellar granule cells and cardiac myocytes during exposure to TETRA fields (380.8875 MHz pulse modulated at 17.6 Hz, 25% duty cycle).

[Ca_{2 +} ](i) was measured as fura-PE3, fluo-3 or fluo-4 fluorescence by digital image analysis.

Results: Granule cells exposed at specific absorption rates (SARs) of 5, 10, 20, 50 or 400 mW . kg(-1) showed no significant changes in resting [Ca(2 +) ](i). Increases in [Ca(2 +) ](i) in response to potassium-induced depolarization were significantly different from sham controls in TETRA-exposed cells, but the majority of the difference was attributable to initial biological variation between cell cultures. No difference was found between fura-PE3 (UV excitation) and fluo-3 (visible light excitation) measurements in these cells. Exposure to TETRA (50 or 400 mW . kg(-1)) had no significant effect on either the rate or amplitude of spontaneous Ca(2 +) transients in cardiac myocytes. The cells showed normal responses to salbutamol (50 microM) and acetylcholine (10 microM).

Conclusions: Overall, these results showed no evidence of any consistent or biologically relevant effect of TETRA fields on [Ca(2 + )](i) in granule cells and cardiac myocytes at any of the SAR tested.