Study type: Medical/biological study (experimental study)

Ultra-wideband pulses increase nitric oxide production by RAW 264.7 macrophages incubated in nitrate. med./bio.

Published in: Bioelectromagnetics 2002; 23 (1): 83-87

Aim of study (acc. to author)

To investigate the possible effects of ultra-wideband pulses (UWB) on the cellular nitric oxide (NO) production.

Background/further details

NO is produced by the enzyme nitric oxide synthase (NOS) and was indirectly measured by determination of nitrite concentration in the media. Nitric oxide synthase is induced (iNOS) by γ-interferon and lipopolysaccharides (LPS).

Endpoint

Exposure

Exposure Parameters
Exposure 1: 84.4 MHz–3.08 GHz
Modulation type: pulsed
Exposure duration: continuous for 30 min

Exposure 1

Main characteristics
Frequency 84.4 MHz–3.08 GHz
Type
Waveform
Charakteristic
  • guided field
Exposure duration continuous for 30 min
Additional info median frequency 0.51 GHz according to Foster PR. 1995. Antennas and UWB signals. In: Taylor JD, editor. Introduction to ultra-wideband radar systems. Boca Raton: CRC Press. p 147-216.
Modulation
Modulation type pulsed
Pulse width 0.98 ns
Rise time 162 ps
Repetition frequency 600 Hz
Additional info

duration of 0.98 ± 0.03 ns and rise time of 162 ± 9 ps

Exposure setup
Exposure source
Chamber Cells were exposed at room temperature (20-25°C) in a custom built GTEM cell, a tapered two conductor transmission line with a square cross section. The UWB exposure system, including the GTEM cell, has been described previously [Lu et al., 1999; Seaman et al., 1999].
Setup Pairs of T75 culture flasks with 235 ml PBS were positioned symmetrically on either side of the midline of the GTEM cell. They stood on end on the horizontal ground plane in the region where a pure TEM wave propagated with the flat growth surface facing the source end. Thus, the growth surface was vertical, parallel to the electric field, and orthogonal to the direction of pulse propagation.
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.106 W/kg - estimated - -
electric field strength 103 kV/m peak value - - ± 7 kV/m
electric field strength 10.6 kV/m peak value estimated - at the PBS surface
magnetic flux density 0.33 mT peak value estimated - -
magnetic flux density 0.2 nT average over time estimated - -

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

An UWB pulse exposure of murine RAW 264.7 macrophage cells, whether stimulated by γ-interferon and lipopolysaccharides or not, did not change the production of nitric oxide. In stimulated cells the NO production increased after UWB exposure when nitrate was added to the media. This indicates a possible action of UWB pulses under certain conditions on iNOS.

Study character:

Study funded by

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