Magnetic fields and lipoic acid influence the respiratory burst in activated rat peritoneal neutrophils

When rat (Sprague-Dawley, male) peritoneal neutrophils are exposed to 60 Hz, 1 Gauss, magnetic fields and activated by phorbor 12-myristate 13-acetate they undergo an enhanced respiratory burst (S. Roy, Y. Noda, V. Eckert, M.G. Traber, A. Mori, R.P. Liburdy, L. Packer, 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, FEBS Lett. 376 (1996) 164-6). In the present study, the reproducibility of these previous findings was confirmed using a new dual-monochrometer exposure system; a 1 Gauss, 60 Hz magnetic field enhanced the production of fluorescence during the respiratory burst. Dose-response studies employed static DC magnetic fields of up to 20 Gauss. Both static DC fields (2.5 and 20 Gauss) showed enhancement of fluorescence production during the respiratory burst. Pre-treatment of neutrophil cells for 10 min at 37 degrees C with an antioxidant, lipoic acid (1-100 µM), significantly elevates fluorescence production in a dose-response manner. The combination of lipoic acid pre-treatment and DC field (2.5 Gauss) exposure further enhanced fluorescence.