Calcium homeostasis of isolated heart muscle cells exposed to pulsed high-frequency electromagnetic fields
- Univ. Bonn (Germany)
- Inst. fuer Nachrichtentechnik Braunschweig (Germany)
The intracellular calcium concentration ([Ca{sup 2+}]{sub i}) of isolated ventricular cardiac myocytes of the guinea pig was measured during the application of pulsed high-frequency electromagnetic fields. The high-frequency fields were applied in a transverse electromagnetic cell designed to allow microscopic observation of the myocytes during the presence of the high-frequency fields. The [Ca{sup 2+}]{sub i} was measured as fura-2 fluorescence by means of digital image analysis. Both the carrier frequency and the square-wave pulse-modulation pattern were varied during the experiments (carrier frequencies: 900, 1,300, and 1,800 MHz pulse modulated at 217 Hz with 14% duty cycle; pulsation pattern at 900 MHz; continuous wave, 16 Hz,and 50 Hz modulation with 50% duty cycle and 30 kHz modulation with 80% duty cycle). The mean specific absorption rate (SAR) values in the solution were within one order of magnitude of 1 mW/kg. They varied depending on the applied carrier frequency and pulse pattern. The experiments were designed in three phases: 500 s of sham exposure, followed by 500 s of field exposure, then chemical stimulation without field. The chemical stimulation (K{sup +}-depolarization) indicated the viability of the cells. The K{sup +} depolarization yielded a significant increase in [Ca{sup 2+}]{sub i}. Significant differences between sham exposure and high-frequency field exposure were not found except when a very small but statistically significant difference was detected in the case of 900 MHz/50 Hz. However, this small difference was not regarded as a relevant effect of the exposure.
- OSTI ID:
- 227889
- Journal Information:
- Bioelectromagnetics, Vol. 17, Issue 2; Other Information: PBD: 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
Intracellular calcium oscillations in a T-cell line after exposure to extremely- low-frequency magnetic fields with variable frequencies and flux densities
Alterations in intracellular ionic calcium levels in isolated adult rat cardiac myocytes due to the generation of free radicals