Magnetic fields increase cell survival by inhibiting apoptosis via modulation of Ca2+ influx

Static magnetic fields with intensities starting from 6 gauss (6X10(-4) tes la, T) were found to decrease in an intensity-dependent fashion, reaching a plateau at 6 X 10(-3) T, the extent of cell death by apoptosis induced by several agents in different human cell systems. This is not due to a change in the mode of cell death (i,e., to necrosis) or to a delay of the process itself; rather, the presence of magnetic fields allows the indefinite surv ival and replication of the cells hit by apoptogenic agents. The protective effect was found to be mediated by the ability of the fields to enhance Ca 2+ influx from the extracellular medium; accordingly, it was limited to tho se cell systems where Ca2+ influx was shown to have an antiapoptotic effect . Magnetic fields thus might interfere with human health by altering/restor ing the equilibrium between cell death and proliferation; indeed, the rescu e of damaged cells may be the mechanism explaining why magnetic fields that are not mutagenic per se are often able to increase mutation and tumor fre quencies.,