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ACTION OF 50 HZ MAGNETIC FIELDS ON NEURITE OUTGROWTH IN PHEOCHROMOCYTOMA CELLS
Citation:
Blackman, C., S. Benane, D. House, AND M. Pollack. ACTION OF 50 HZ MAGNETIC FIELDS ON NEURITE OUTGROWTH IN PHEOCHROMOCYTOMA CELLS. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-93/392 (NTIS PB93236305).
Description:
This study tests the capacity of 50-Hz magnetic and electric fields to stimulate neurite outgrowth in PC-12D cells, a cell line which originated from a pheochromocytoma in rat adrenal medulla. he cells were plated on collagen-coated plastic petri dishes and exposed to sinusoidal 50-Hz magnetic fields for 22 hours in a 5% CO2 incubator at 37 degrees C. wo 1000-turn coils, 20 cm in diameter, were assembled in a Helmholtz configuration to generate a magnetic field in a vertical orientation, thereby inducing a companion electric field in the dish with intensity proportional to medius. o-netic metal magnetic-field shield housed the control samples in the same incubator. otal cells and number of cells with neurites at least as long as one cell diameter or having a growth cone were counted wi@ a radius of 0.3 cm of the dish center and within an annulus of 1.7 to 1.8 cm radii in 60-mm dishes, at 3.6 cm radius in 100-mm dishes, and between 1.9 and 2.1 cm radii in the outer well of organ culture dishes, which are physically separated into two concentric wells. ham exposure demonstrated no difference in percentage of cells with neurites between the exposed and control locations in the incubator. xposures were done at 4.2, 9.0, 22, 31, 42, 120, 230 and 420 milligauss (mG). t dish radii of 1.7 - 1.8 cm in the 60-mm dishes these magnetic flux densities induced electric fields of 1.2, 2.5, 6.0, 8.5, 12. 33, 63 and 115 uV/m, respectively, while within a radius of 0.3 cm, the induced electric fields were less 0.2, 0.4, 1.0, 1-5, 2.0, 6.0., 11 and 20 uV/m, respectively. or other dishes, the larger radii produced proportionally larger induced magnetic fields. t each field strength, there were two control dishes and four to nine exposed dishes; 100 or more cells were counted a each dish location. he results demonstrate that magnetic fields stimulate neurite outgrowth in a field strength-dependent manner between 22 and 42 mG, reaching an apparent stimulation plateau between 42 and 420 mG; no effects were seen at 9 mG or lower. There was no apparent neurite stimulation due to the electric field. lthough relatively low intensity (> 22 mG) magnetic fields alone can stimulate a morphological response in a cell which is normally stimulated by nerve-growlh-factor molecules binding to membrane receptors, the chemical basis of this response is unknown.