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EMPIRICAL TEST OF AN ION PARAMETRIC RESONANCE MODEL FOR MAGNETIC FIELD INTERACTIONS WITH PC-12 CELLS
Citation:
Blackman, C., J. Blanchard, S.G. Benane, AND D. House. EMPIRICAL TEST OF AN ION PARAMETRIC RESONANCE MODEL FOR MAGNETIC FIELD INTERACTIONS WITH PC-12 CELLS. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-95/135, 1994.
Description:
A companion paper [Blanchard and B 19931 describes a predictive heuristic ion parametric resonance (IPR) model of magnetic field interactions with biological systems based on a selective relation between the ratio of the static magnetic field to the frequency of the AC magnetic field and the charge-to-mass ratio of ions of biological relevance. revious studies demonstrated that nerve growth factor (NGF) stimulated neurite outgrowth (NO) in PC-12 cells can be inhibited by exposure to magnetic fields as a function of either magnetic field flux density or AC magnetic field frequency. he present work examines whether the PC-12 cell response to magnetic fields is consistent with the predictions of the IPR model. e tested changes in each of the experimentally controllable variables [flux densities of the parallel components of the AC magnetic field (B.) and the static magnetic field (Bd,), and the frequency of the AC magnetic field] over a range of exposure conditions sufficient to determine whether the IPR model is applicable. e used a multiple-coil exposure system for independent control of each of these critical quantities. he ambient perpendicular static magnetic field was less than 2 mG for all tests. he first set of tests examined the NO response in cells exposed to 45-Hz B. from 77 to 468 milligauss (rms) at a Bdc of 366 milligauss. ext we examined an off-resonance condition using 20 milligauss Bdc with a 45 Hz AC-field across a range of Bdc Finally, we changed the AC frequency to 25 Hz, with a corresponding change in Bd (to 203 mG (to tune for the same set of ions as in the first test) and a B. range from 78 to 181 mG (rms). n all cases the observed responses were consistent with predictions of the EPR model. hese experimental results are the first to support in detail the validity of the fundamental relationships embodied in the IPR model. f particular note is the fact that as the AC flux density increases, the response. is non-linear. his contrasts with the concept that there is a threshold above which increasing exposure produces more effect.