Study type: Medical/biological study (experimental study)

Differentiation of murine erythroleukemic cells during exposure to microwave radiation med./bio.

By: Brown RF, Marshall SV
Published in: Radiat Res 1986; 108 (1): 12-22
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Aim of study (acc. to editor)

To study the effect of 1180 MHz microwave radiation on proliferation and differentiation of mammalian cells (murine erythroleukemic cells, MEL) in the absence of hyperthermia.

Background/further details

MEL cells form hemoglobin and show other expressions of erythroid differentiation in response to inducers such as hexamethylene bisacetoneamide, HMBA.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1,180 MHz
Modulation type: CW
Exposure duration: continuous for 48 h

Exposure 1

Main characteristics
Frequency 1,180 MHz
Type
Exposure duration continuous for 48 h
Modulation
Modulation type CW
Exposure setup
Exposure source
Distance between exposed object and exposure source 42.5 cm
Chamber A small anechoic chamber made of 1.22 x 1.22-m plywood sheets and lined with MW absorbent pyramids was circulated via a closed-loop Styrofoam duct by warmed air maintained at 37.4 ± 0.2°C.
Setup Two sealed thin-walled cellulose nitrate culture tubes (1.6 x 10 cm) containing 12 ml of culture medium were positioned horizontally 6.7 cm apart in the Styrofoam air duct parallel to the E field and equidistant from the antenna by means of a holder (10.2 x 12.6 cm) made of 1-mm balsa sheets with a series of criss-crossed air diffuser vanes.
Additional info Each experiment included two MW irradiated cultures and two non-irradiated controls incubated in a 37.4°C water bath. Irradiated cultures were rotated after 24 h.
Parameters
Measurand Value Type Method Mass Remarks
power density 5.5 mW/cm² - calculated - -
SAR 18.5 W/kg mean measured - -
power density 11 mW/cm² - calculated - -
SAR 36.3 W/kg mean measured - -
power density 22 mW/cm² - calculated - -
SAR 69.2 W/kg mean measured - -
Additional parameter details

The average of power density values measured was about 6% higher than those calculated.

Measurement and calculation details

Power density was calculated from geometry and forward and reflected powers measured by power meters via a dual directional coupler. A broadband radiation meter was used to measure the uniformity of the field. SAR was determined by two methods, one using temperature probes and 60-s decay curves and the other involving Dewar calorimetry [Durney et al., 1980].

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Mean cell doubling time was the same in both the irradiated cultures and the control cultures (16.5 h). About 65% of the cells of exposed cultures and control cultures were benzidine-positive differentiated cells. Both the exposed cultures and control cultures contained approximately 58 µg of hemoglobin/mg total cytoplasmic protein. The absence of any change in these parameters suggests that microwave exposition at 1180 MHz and similar frequencies exerts no effect on proliferation and differentiation of mammalian cells in the absence of hyperthermia.

Study character:

Study funded by

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