The Clastogenic Effects of Cyclophosphamide and a Sixty Hertz Electronagnetic Field on Bone Marrow Cells of CD-I Mice
Date of Award
Doctor of Philosophy
Dr. Robert H. Poel
Dr. Gyula Ficsor
Dr. Leonard Ginsberg
Extremely low frequency (ELF) electromagnetic fields (EMF) have been correlated with the induction of cancer in a number of epidemiological studies (Feychting and Ahlbom, 1993; T,m and Lee, 1994; London e t al. 1991; Lovely et al., 1994; Tomenius, 1986; Wertheimer and Leeper, 1979, 1982). Two hypothesis were tested in the present study. The first hypothesis tested was that exposure to a 7.3 G magnetic field for 24 hours would increase the frequency of clastogenic and/or mutagenic events in bone m arrow cells of mice. The second hypothesis tested was that exposure to a 7.3 G magnetic field for 24 hours would increase the frequency of clastogenic and/or mutagenic events in bone marrow cells of mice also treated with cyclophosphamide, and hence may enhance the potential for cancer initiation by a known clastogen, mutagen, and carcinogen (Povirk and Shuker, 1994).
Eight groups of mice, 12 animals per group (6(m) and 6(f)), were administered a single Lp. injection of cyclophosphamide at a dose of 0, 5, 25, or 50 mg/kg b.w.. Each group of mice was separated by sex into two plastic cages and the two cages placed side-by-side within the center region of an energized or nonenergized Helmholtz coiL The 60 Hertz alternating current was regulated to flow through the coil for 19 seconds, followed by a 19 second interval of no current flow, ad infinitum As measured, the energized coil produced a magnetic field intensity of 7.3 gauss and an electric field intensity of 17.0 V/m at the center region of the coil.
After 20 hours of ELF EIMF or sham exposure, the mice were injected with a single i.p. injection of colchicine at a dose of 4 mg/kg b.w., and returned to their cage within the coil for 4 more hours of ELF EM F or sham exposure. After 24 hours of ELF E M F or sham exposure, the mice were sacrificed by cervical dislocation, their femurs removed, and bone marrow metaphase spreads prepared on glass slides.
The scoring of the slides revealed that a 24 hour exposure to a magnetic field intensity of 7.3 G did not significantly increase the firequency of clastogenic and/or mutagenic events in mice that had (or had not) been treated with cyclophosphamide. The results did not support either of the two research hypothesis tested in the present study.
Block, Kevin K., "The Clastogenic Effects of Cyclophosphamide and a Sixty Hertz Electronagnetic Field on Bone Marrow Cells of CD-I Mice" (1997). Dissertations. 1649.
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