ID Number		296
Study Type		In Vivo
Model		50-60 Hz (ELF) exposure to rats and analysis of cancer (DMBA-initiated mammary tumor model).
Details		In a series of experiments with the chemical carcinogen DMBA (7, 12-dimethyl[a]anthracene), it was found that exposure of female Sprague-Dawley rats in 50 Hz magnetic fields (MF) in the microtesla range significantly facilitates the development and growth of mammary tumors. One possible explanation for this finding would be enhanced proliferation of breast epithelial stem cells by MF exposure, thereby increasing the sensitivity of these cells to chemical carcinogens. In line with this possibility, it was determined that 50 Hz, 50 microT MF exposure induces increases in ornithine decarboxylase (ODC), i.e., a key enzyme in cell proliferation, in the mammary gland of female Sprague-Dawley rats. In the present study, the time course of this effect was examined, by using different periods of exposure to a 50 Hz, 100 microT MF. Furthermore, ODC in different mammary complexes of the rat mammary gland was determined to evaluate whether differences in response to MF exist over the anterior-posterior extension of this organ. Exposure of young female Sprague-Dawley rats induced marked increases in ODC in the mammary gland that were similar to ODC increase seen in "positive control" experiments with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). Other studies found decreased T-cell proliferation and immune response.
Findings		Effects
Status		Completed With Publication
Principal Investigator		University of Hannover - wloscher@pharma.tiho-hannover.de
Funding Agency		BfS, Germany
Country		GERMANY
References		Mevissen, M et al. J Toxicol Environ Health, (1998) 53:401-418 Mevissen, M et al. J Toxicol Environ Health, (1996) 48:169-185 Mevissen, M et al. Carcinogenesis, (1996) 17:903-910 Loscher, W et al. Oncology, (1994) 51:288-295 Loscher, W et al. Cancer Lett., (1993) 71:75-81 Baum, A et al. Carcinogenesis, (1995) 16:119-125 Mevissen, M et al. Bioelectromagnetics, (1999) 20:338-346 Mevissen, M et al. Bioelectromagnetics, (1998) 19:259-270 Haussler, M et al. Bioelectromagnetics, (1999) 20:295-305 Loscher, W et al. Cancer Lett, (1995) 96:175-180 Mevissen, M et al. Cancer Lett, (1995) 90:207-214 Mevissen, M et al. Bioelectromagnetics, (1993) 14:131-143 Fedrowitz, M et al. Cancer Research., (2004) 64:243-251
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