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Serum plays a critical role in modulating [Ca 2+ ] c of primary culture bone cells exposed to weak ion‐resonance magnetic fields
Author(s) -
Reinbold Kirk A.,
Pollack Solomon R.
Publication year - 1997
Publication title -
bioelectromagnetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.435
H-Index - 81
eISSN - 1521-186X
pISSN - 0197-8462
DOI - 10.1002/(sici)1521-186x(1997)18:3<203::aid-bem2>3.0.co;2-6
Subject(s) - nuclear magnetic resonance , bioelectromagnetics , ion , magnetic resonance imaging , primary (astronomy) , medicine , biophysics , chemistry , physics , magnetic field , biology , radiology , organic chemistry , quantum mechanics , astronomy
Primary‐culture bone cells were exposed to ion‐resonance (IR) magnetic fields tuned to Ca 2+ . Cytosolic calcium concentration, [Ca 2+ ] c , was measured by using fura‐2 during field exposure. The fields investigated were 20 μT static + 40 μT p‐p at either 15.3 or 76.6 Hz, and 0.13 mT static + either 0.5 or 1.0 mT p‐p at 100 Hz. Other parameters included field orientation, culture age (2 or 5 days after plating), and the presence of serum (0 or 2%) during exposure. Total experiment time was 29.5 min: The field was applied after 2 min, and bradykinin was added as an agonist control after 22 min. The data were quantified on a single‐cell basis during the 2–22 min exposure period in terms of the magnitude of the largest occurring [Ca 2+ ] c spike normalized to local baseline. Field‐exposed and control groups were characterized in terms of the percent of cells exhibiting spike magnitudes above thresholds of 100 or 66% over baseline and were compared by using Fisher's exact test. Without serum, there was little evidence that IR magnetic fields altered [Ca 2+ ] c . However, in the presence of 2% serum, 3 of the 16 experiments exhibited significant effects at the 100% threshold. Reducing this threshold to 66% resulted in five experiments exhibiting significant effects. Most strikingly, in all of these cases, the field acted to enhance [Ca 2+ ] c activity as opposed to suppressing [Ca 2+ ] c activity. These findings suggest a role for serum or for constituents within serum in mediating the effects of IR magnetic fields on cells and may provide a resolution pathway to the dilemma imposed by theoretical arguments regarding the possibility of such phenomena. Possible roles of serum and future studies are discussed. Bioelectromagnetics 18:203–214, 1997. © 1997 Wiley‐Liss, Inc.