Study type: Medical/biological study (experimental study)

Inhibition of the production of reactive oxygen species in mouse peritoneal neutrophils by millimeter wave radiation in the near and far field zones of the radiator med./bio.

By: Gapeyev AB, Safronova VG, Chemeris NK, Fesenko EE
Published in: Bioelectrochem Bioenerg 1997; 43 (2): 217-220
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Aim of study (acc. to author)

To investigate the effects of electromagnetic irradiation on the production of reactive oxygen species (ROS) in mouse neutrophils in vitro by using luminol-dependent chemiluminescence technique.

Background/further details

The cells were activated by opsonized zymosan.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 41.75–42.15 GHz
Modulation type: CW
Exposure duration: continuous for 40 min
Exposure 2: 41.95 GHz
Modulation type: CW
Exposure duration: continuous for 40 min

Exposure 1

Main characteristics
Frequency 41.75–42.15 GHz
Type
Exposure duration continuous for 40 min
Additional info Eight or nine frequencies were tested for both near and far field conditions.
Modulation
Modulation type CW
Exposure setup
Exposure source
  • waveguide
  • channel radiator with 17.5 x 12.5 mm aperture
Chamber Four experimental 200-µl cuvettes were fixed in a holder at room temperature and irradiated from the side of the 0.3-mm thick cuvette bottom to which the cells were spontaneously attached.
Setup The distance from the antenna face was 65 mm for near and 400 mm for far field exposure.
Additional info In the near field zone, the holder was positioned at an angle of 75° between the object plane and the wave propagation direction resulting in an SWR between 1 and 1.2 in the whole frequency range used.
Parameters
Measurand Value Type Method Mass Remarks
power density 240 µW/cm² mean measured and calculated - near field
power density 150 µW/cm² mean measured and calculated - far field
Measurement and calculation details

In the near field zone, the SAR was determined from the heating rate using a micro thermocouple. The absorbed energy flux density (AEFD) in a thin cell layer of about 0.1-0.2 mm was calculated from the SAR, the real square of the cuvette bottom and the weight of the water solution. The radiation geometry evaluated using IR thermography showed a uniform SAR distribution in the frequency range used. In the far field zone, the AEFD was estimated from the energy flux density measured using a radiation detector. The output wave frequency was controlled using a wavemeter.

Exposure 2

Main characteristics
Frequency 41.95 GHz
Type
Exposure duration continuous for 40 min
Additional info near and far field
Modulation
Modulation type CW
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
power density 2,400 µW/cm² maximum measured and calculated - near field
power density 0.05 µW/cm² minimum measured and calculated - near field
power density 150 µW/cm² maximum measured and calculated - far field
power density 0.025 µW/cm² minimum measured and calculated - far field
Additional parameter details

Seven energy levels were tested for both near and far field conditions.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

A frequency-dependent inhibition of ROS production was observed in the near field zone, whereas the inhibition in the far field zone was not frequency-dependent.

Study character:

Study funded by

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