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Calcium signaling in lymphocytes and ELF fields Evidence for an electric field metric and a site of interaction involving the calcium ion channel
Author(s) -
Liburdy Robert P.
Publication year - 1992
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(92)80209-y
Subject(s) - calcium , electric field , extracellular , biophysics , calcium signaling , calcium in biology , t type calcium channel , chemistry , voltage dependent calcium channel , calcium metabolism , nuclear magnetic resonance , biochemistry , biology , physics , organic chemistry , quantum mechanics
Calcium influx increased during mitogen‐activated signal transduction in thymic lymphocytes exposed to a 22 mT, 60 Hz magnetic field ( E induced =1.7 mV/cm. 37°C, 60 min). To distinguish between an electric or a magnetic field dependence a special multi‐ring annular cell culture plate based on Faraday's Law of Induction was employed. Studies show a dependence on the strength of the induced electric field at constant magnetic flux density. Moreover, exposure to a pure 60 Hz electric field or to a magnetically‐induced electric field of identical strength resulted in similar changes in calcium transport. The first real‐time monitoring of [Ca 2+ ] i during application of a 60 Hz electric field revealed an increase in [Ca 2+ ] i observed 100 s after mitogen stimulation; this suggests that the plateau phase rather than the early phase of calcium signalling was influenced. The hypothesis was tested by separating, in time, the early release of calcium from intracellular stores from the influx of extracellular calcium. In calcium‐free buffer, 60 Hz fields exerted little influence on the early release of calcium from intracellular stores. In contrast, addition of extracellular calcium during exposure enhanced calcium influx through the plasma membrane. Alteration of the plateau phase of calcium signalling implicates the calcium channel as a site of field interaction. In addition, an electric field exposure metric is mechanistically consistent with a cell‐surface interaction site.