ID Number		793
Study Type		In Vitro
Model		2450 MHz (CW) exposure to various cell lines and analysis of growth and enzyme activity
Details		L929 murine lung epithelial cells, as well as human IMR-90 and XP-12BE cells, were exposed to 2450 MHz MW at 0.013, 0.026, 0.039, 0.13, and 1.3 W/kg for 4 hours. Exposure resulted in no changes in cell viability or proliferation rate in any cell type. In addition, exposure of L929 cells at 0.13 W/kg (as above) was performed followed by incubation for 18 hours and the activity of interferon regulated 2'-5' oligoadenylate synthetase (2-5 A) and 2'-5' oligoadenylate ribonuclease (RNase L) was analyzed. The authors reported no effect of non-thermal MW exposure on cell viability or proliferation rate. Further, the lack of a negative effect on XP cells, deficient in DNA damage repair, makes a direct damage to the DNA unlikely. In cells exposed as above followed by incubation for 18 hours, however, the activity of 2'-5' oligoadenylate ribonuclease (RNase L) binding to 2'-5' A and subsequent RNase activity was increased, although no change was reported in the activity of interferon regulated 2’-5’ oligoadenylate synthetase (2-5 A) The authors conclude that, although exposure did not affect cell viability, direct DNA damage, or proliferation rate, it may have effects on certain enzyme activity.
Findings		Effects
Status		Completed With Publication
Principal Investigator		Catholic University of America, Washington D.C., U
Funding Agency		Private/Instit.
Country		UNITED STATES
References		Krause, D et al. Radiat. Res., (1991) 127:164-170
Comments		There was no positive control for the enzyme activity measurements. There was also no temperature monitoring during exposure. Sham exposure alone resulted in a ~14% increase in 2’-5’ A binding and RNase L activity indicating that some of the effects might have been induced by the manipulation of the cells during exposure, trypsinization, or re-plating steps. Further, enzyme activity should have also been assayed following exposure at the higher dose level (1.3 W/kg – used for cell viability and proliferation assays in the same paper) to achieve a potential dose response to better verify and characterize the finding.