Rat alveolar macrophages (NR8383 cell line) were incubated for 24 h with 10% plasma from male Sprague-Dawley rats that had been exposed to sham exposure conditions (plasma of three sham exposed rats), or exposed to 42°C (n=3, as positive control) environmental heat or 35 GHz millimeter waves (n=3) until core temperature reached 41°C.
The authors hypothesized that 35 GHz millimeter waves can elicit the release of biologically active mediators into the systemic blood circulation leading to downstream responses in cells and tissues. Use of an in vitro assay allows delineation of effects induced by plasma-borne compounds from the direct effects of heating that would likely be exhibited by macrophage cells derived from the millimeter wave-exposed rats. Macrophages were selected because they have a major role in immune system functions, and, were shown in previous studies to be affected by millimeter wave exposure (see "related articels").
As a positive control for Western blot macrophages were treated for 24 h with a mixture of lipopolysaccharide and recombinant rat IFN-gamma in culture medium.
|Distance between exposed object and exposure source||110 cm|
|Setup||conical horn antenna with an aperture of 6.8 cm; anesthetized rats placed on a stand with the clipped side of the body centered along the boresight of the horn antenna|
|Sham exposure||A sham exposure was conducted.|
Compared to plasma from sham exposed rats, plasma from heat or millimeter wave exposed rats increased the expression of 11 proteins, and levels of 3-nitrotyrosine in seven proteins, in the NR8383 cell line. These altered proteins are associated with inflammation, oxidative stress, and energy metabolism.
Findings of this study indicate both environmental heat and 35 GHz millimeter wave exposure elicit the release of macrophage-activating mediators into the plasma of rats.