The effect of exposure to high flux density static and pulsed magnetic fields on lymphocyte function

We investigated whether a combination of static electromagnetic field (EMF) at a flux density of 4.75T together with pulsed EMF at a flux density of 0.7 mT generated by an NMR apparatus (NMRF), could promote movements of Ca2þ, cell proliferation, and the eventual production of proinflammatory cytokines in human lymphocytes as well as in Jurkat cells, after exposure to the field for 1 h. The same study was also performed after activation of cells with 5 mg/ml phytohaemagglutinin (PHA) immediately before the exposure period. Our results clearly demonstrate that NMRF exposure increases the [Ca2þ]i, without any proliferative, or activating, or proinflammatory effect on both normal and PHA stimulated lymphocytes. Accordingly, the levels of interferon g, tumor necrosis factor a, interleukin-1b, interleukin-2, and interleukin-6 remained unvaried after exposure. Exposure of Jurkat cells statistically decreased the [Ca2þ]i and the proliferation. This is consistent with the low levels of IL-2 measured in supernatants of these cells after exposure. On the whole our data suggest that static and pulsed NMRF exposure contribute synergistically in the increase of the [Ca2þ]i without any activating or proinflammatory effect either in normal or in PHA challenged lymphocytes. In Jurkat cells, by changing the properties of cell membranes, NMRF exposure can influence Ca2þ transport processes and hence Ca2þ homeostasis, causing a marked decrease of proliferation.