THE PHORBOL 12-MYRISTATE 13-ACETATE (PMA)-INDUCED OXIDATIVE BURST IN RAT PERITONEAL NEUTROPHILS IS INCREASED BY A 0.1 MT (60 HZ) MAGNETIC-FIELD

Magnetic fields (MF) may affect biological systems by increasing free radical concentrations. To test this, we have investigated whether low frequency (60 Hz) low intensity (0.1 mT) MF can modulate the phorbol 12-myristate 13- acetate (PMA) induced respiratory burst in primed rat peritoneal neutrophils, followed in real time using the dye 2',7'-dic hlorofluorescin (DCFH), which reacts with free radical-derived oxidant s such as H2O2 (which is formed from the dismutation of superoxide) to become 2',7'-dichlorofluorecein (DCF), a highly fluorescent compound. In the presence of the MF, a 12.4% increase in the fluorescence signa l was observed in PMA-stimulated neutrophils (n = 5, P < 0.02, 18 pair s of measurements). We believe this represents the first experimental observation of MF influencing events involving free radical species ge nerated during signal transduction in living cells.